Chemical and Physical Properties of Sodium

Sodium is a chemical element that has been used by humans since the ancient times. It is the most important metal from a commercial point of view, as it is utilized by both organic and inorganic industries. Properties of sodium make it a unique element and here, we give you more information about the chemical and physical properties of sodium.
Did you know...

... that the name sodium is derived from the Arabic word 'suda' which means headache; as sodium carbonate or soda was used to alleviate headaches in ancient times.

Since sodium as a metal does not occur in the free form naturally, it has to be isolated from compounds and this was first done by Sir Humphry Davy in England in 1807. Sodium is a member of the alkali metal group and is placed in the periodic table below lithium and above potassium. It is the most abundant of all alkali metals. Chemically, sodium is represented by the symbol Na. Atomic number of sodium is 11 and its atomic mass is 22.98. As the atomic number of sodium suggests, it has only one electron in its outermost orbit or its valency is +1. Due to this, sodium is a highly reactive chemical element and is found only in the form of compounds. There are 20 known isotopes of sodium but only one 23Na is found to be stable. With changes in the surrounding physical conditions, the properties of this element change.

Chemical Properties of Sodium

Chemical properties are all those properties that are visible only when any reaction is taking place between sodium and any other chemical substance. As per the periodic table, sodium is more reactive than lithium and less reactive than potassium.

Oxygen
Sodium readily reacts with oxygen to form sodium oxide. When pure form of sodium comes in contact with air, it forms sodium oxide instantly, and this oxide forms a white coating and protects the underlying metal from any further reaction. Hence it is often kept in oil to prevent it from reacting with oxygen. When sodium is burnt in air, it reacts with atmospheric oxygen to form sodium peroxide (Na2O2). Whereas on burning in limited supply of oxygen, it forms sodium oxide (Na2O). If this burning process is carried out under pressure, sodium superoxide (NaO2) is formed.

Hydrogen
Reaction of sodium with hydrogen at a temperature of above 392 °F (200 °C) results in the formation of sodium hydride ( NaH). Sodium hydride is a compound which decomposes but does not melt at 752 °F (400 °C).

Water
Reaction of sodium with water and even with snow and ice results in the formation of sodium hydroxide and hydrogen gas. As heat is produced during this reaction, it is called exothermic reaction. This released heat often ignites the hydrogen gas and as a result a fire may break out. If large pieces of sodium are put into water it can lead to a loud explosion.

Air
Sodium is more reactive in air when in a liquid state than in a solid state. Metallic sodium reacts with ordinary air to form a thin sodium hydroxide film (NaOH). It further absorbs carbon dioxide from the air to form sodium bicarbonate (NaHCO3). In a dry air atmosphere, sodium burns by giving away a dense white caustic smoke. Oxidation of sodium in dry air will result into sodium monoxide (Na2O).

Ammonia
Under two different conditions, reaction of sodium with ammonia yields two different products. When the reaction takes place in the presence of hot coke or pure carbon, then sodium cyanide (NaCN) and hydrogen are obtained. On reaction with liquid ammonia, where iron, cobalt or nickel act as catalyst, sodium amide (NaNH2) and hydrogen gas are formed.

Unsaturated Hydrocarbons
Sodium reacts with hydrocarbon compounds with double bonds to make them saturated (single bonded). This type of reaction is often referred to as addition reaction.

Mercury
It also reacts with mercury to form a sodium amalgam which is an alloy of mercury and sodium.

Alcohol
On addition of sodium into alcohol, a compound is formed, which is called alkoxide. This reaction has some similarity with sodium's reaction with water as in both the cases it replaces one hydrogen atom.

Sulfuric acid
Sodium dissolves in diluted sulfuric acid and this results in the formation of solutions that has aquated Na(I) ions along with hydrogen gas.

Halogens
Sodium reacts vigorously with fluorine and chlorine at room temperature. It also reacts vigorously with bromine and iodine but only in the vaporous phase. This reaction results in the formation of sodium fluoride (NaFl), sodium chloride (NaCl), sodium bromide (NaBr) and sodium iodide (NaI).

Alkenes and Dienes
When sodium comes into contact with alkenes and dienes, it forms additional products. One such product formed the basis of making an early synthetic rubber known as buna rubber.

Organic Halides
Sodium reacts with organic halides in two ways. In the first reaction, the two organic compounds need to be condensed. This results in formation of halogens when they are eliminated. It is necessary for the second reaction to replace the halogen by sodium. This results in sodium organic compound.

Nitrogen
Sodium does not react with nitrogen, hence it is usually stored by immersing in nitrogen atmosphere or in inert liquids like kerosene or naphtha.

Physical Properties

Physical properties are those aspects of the element that can be perceived or measured. These include density, melting point, boiling point, electric conductivity, etc.

General Properties

Symbol Na
Atomic Number 11
Relative Atomic Mass 22.9897 amu
Family Group 1 (IA)
Alkali metal
Atomic Radius 186 pm
Electronic Shell [Ne]3s1
Oxidation States +1, -1
Crystal Structure body centered cubic
Magnetic Ordering paramagnetic
Electron Configuration 2,8,1
Electronegativity 0.93


Physical Properties
Phase (at r.t.) Solid
Density (near r.t.) 0.968 g·cm−3
Liquid density at m.p. 0.927 g·cm−3
Melting point 370.87 K, 97.72 °C, 207.9 °F
Boiling point 1156 K, 883 °C, 1621 °F
Critical point (extrapolated)
2573 K, 35 MPa
Heat of fusion 2.60 kJ·mol−1
Heat of vaporization 97.42 kJ·mol−1
Molar heat capacity 28.230 J·mol−1·K−1

Sodium has a body-centered cubic (bcc) structure. It has a hardness of 0.5 mohs. At room temperature, sodium is found in the form of a solid metallic substance which is very soft to touch. Due to its softness, you can easily cut it with the help of a table knife. If the surface of sodium is freshly cut, it will oxidize rapidly in the air to form an oxide coating.

Sodium not exposed to air is silvery-white in color and is bright and shiny. When it is exposed to air, it becomes dull and gray because of the reaction with the oxygen present in the atmosphere. Freshly exposed sodium is lustrous and is usually bright silver in color. However, due to tarnishing a white-colored coating of sodium hydroxide and sodium carbonate in formed. Exposure at elevated pressure of 1.5 Mbar changes its color to black and turns transparent red in color at 1.9 Mbar. On further exposure at elevated pressure it turns transparent at 3 Mbar. Sodium's compounds are white in color.

Sodium has extremely low density and it is a bit lower than that of water. For this reason, if you place it in water, it will float. Though after some time, it will react violently on contact with water and release large amounts of heat that may result in outbreak of flames. Sodium or it's compounds can turn a flame yellow and can burn in the air with a brilliant yellow flame. Both the melting and boiling point of sodium are quite high. Its boiling point is at 883° C and melting point is at 97.72° C. Sodium is a good conductor of electricity, which means that electric current can pass through this element without much resistance.

Sources

✦ Abundant sodium is found in the sun and stars. The dominant yellow component in their light is the result of sodium atoms in a high-energy state.

✦ The D lines of sodium can be easily seen in the solar spectrum.

✦ Sodium is the sixth most abundant element in the Earth's crust and contains 2.6% of sodium(by weight) in all its forms.

✦ Also, sodium is the second most abundant element which is dissolved in sea water.

✦ It is also found in salty lakes, alkaline lakes and mineral spring water.

✦ Sodium chloride (salt) is the most common sodium compound.

✦ It is also found in many minerals like cryolite, soda niter, zeolite, amphibole and sodalite.

✦ Other forms of sodium are washing soda (Na2CO3), baking soda (NaHCO3), Chili saltpeter (NaNO3) which is sodium nitrate.

Uses

✦ Sodium chloride (table salt, NaCl) is essential for human and animal nutrition.

✦ Sodium ions are instrumental for the transmission of electrical signals in the nervous system and to regulate the water balance between body cells and body fluids.

✦ Sodium compounds are also used in making glass, paper, textile, and in metal industries.

✦ Compounds of sodium are also used for the purpose of making soaps, petroleum and chemicals.

✦ Sodium vapor lamps are energy-efficient and are used in street lights.

✦ Metallic sodium is used to manufacture sodium peroxide, sodium cyanide, sodamide, and sodium hydride.

✦ Liquid sodium is used as a heat transfer agent to cool nuclear reactors.

✦ Sodium is also used in making tetraethyllead which is used as an additive in aviation fuel.

✦ Sodium is also used to reduce organic esters and preparing organic compounds.

✦ Sodium is utilized for modifying the structure of alloys and, enhancing their mechanical properties along with fluidity.

✦ Sodium is also used for descaling metal and purifying molten metals.

Though it is an abundantly available metal, sodium cannot be found freely in nature. It is derived after the electrolysis of dry fused sodium chloride. Some of the reactions are binary (formed by two elements), some are ternary (formed by three elements) and others have more complex forms. All these chemical and physical properties of sodium are responsible for the formation of such a large variety of sodium compounds in nature. Sodium, though not toxic, can cause burns and irritation when it comes in contact with human skin. Do not forget, a fire induced by sodium requires dry-powder fire extinguishers, as sodium reacts with carbon dioxide present in regular extinguishers.

Best Assault Rifles

Rifles were invented for protection as well as destruction. They are collectors' items and symbol of power. This article takes a shot at listing down some of the best assault rifles available all over the world.
Phillip Killicoat, an Oxford Economist, provided some interesting statistics in his 2006 paper, Weaponomics: The Economics of Small Arms. There are around 500 million firearms in the world, out of which 100 million of them are from Kalashnikov family; however, AK-47 dominates the weapon market with 75 million units in existence.

A standard infantry weapon used in modern warfare and in armies all over the world is the most basic definition of an assault rifle. These big-boy guns come with features like intermediate cartridge, detachable magazine, and selective fire choice (selective fire between automatic, semiautomatic, and burst-fire). Within the category of assault rifles, you have two types of firearms. They are: light machine guns and submachine guns. The former is used for sustained automatic fire, which fires full-powered cartridges in a light support role. The latter fires a lower-powered pistol cartridge. Interestingly, it was Adolf Hitler who introduced the term 'assault rifle' to the world, which is derived from the German word Sturmgewehr.

The Best of Their Kind


AK-47

Type - Selective fire (Semi or fully automatic assault rifle)

Rate of Fire - Cyclic 600 rounds/min, semi-automatic-40 rounds/min, fully automatic - 100 rounds/min

Caliber of Bullet - 7.62×39mm (.30 inch)

Muzzle Velocity - 2,350 ft/s

Magazine Capacity - 30 rounds

Country of Origin - Soviet Union

Special Features - Being simple in its design and compact in size, the AK-47 is easy to manufacture, clean, and maintain. It has become the most popular firearm worldwide due to its robustness and good success rate. It is a weapon of choice of the armed and special forces of more than 80 countries.

M16

Type - Selective fire (Semi or fully automatic assault rifle)

Rate of Fire - (full-auto cycle) 700-950 rounds/min

Caliber of Bullet - 5.56×45mm NATO cartridge

Muzzle Velocity - Approximately 3,110 ft/s

Magazine Capacity - 20-30 rounds

Country of Origin - United States

Special Features - Superb accuracy, handling, service length, and combat effectiveness are a few of its USP as it has a lightweight weapon with metal alloy and plastic construction.


FN FAL 50.00

Type - Self-loading, selective fire

Rate of Fire - 650-700 rounds/min

Caliber of Bullet - 7.62×51mm (.30 inch)

Muzzle Velocity - 2,756 ft/s

Magazine Capacity - 20 or 30 rounds for detachable box magazine; 50 round drum also available.

Country of Origin - Belgium

Special Features - Being used in over 90 countries worldwide, it has been described as "The Right Arm of the Free World".


Steyr AUG

Type - Semi or fully automatic bullpup assault rifle

Rate of Fire - 680-750 rounds/min

Caliber of Bullet - 5.56×45mm NATO, 9×19mm Parabellum

Muzzle Velocity - 3,182 ft/s

Magazine Capacity - 30 and 42 rounds

Country of Origin - Austria

Special Features - Boasts of an interchangeable barrel system, transparent magazine, and an optional left or right shell ejection capability.


AR-15

Type - Semi-automatic rifle

Rate of Fire - 800 rounds/min (fully automatic versions only)

Caliber of Bullet - .223 Remington, 5.56 NATO

Muzzle Velocity - 3,200 ft/s

Magazine Capacity - 10-30 rounds

Country of Origin - United States

Special Features - The AR 15 is fully loaded with features like aluminum receiver and it is lightweight, highly corrosion-resistant, and machinable. It's a modern design that makes way for accessories, such as after market sights, vertical forward grips, lighting systems, night vision devices, laser targeting devices, muzzle brakes/flash hiders, sound suppressors, bipods, etc.


SG 550

Type - Selective fire

Rate of Fire - Approx. 700 rounds/min

Caliber of Bullet - 5.6mm Gw Pat 90 (5.56×45mm NATO)

Muzzle Velocity - 2,989 ft/s

Magazine Capacity- 5, 20, 30-round detachable box magazine

Country of Origin - Switzerland

Special Features- The most unique feature about this rifle is that it comes with a 30-round magazine that is molded from a translucent polymer, which can be locked together using connectors so as to facilitate Jungle-style loading.


G36K

Type - Semi-automatic

Rate of Fire - 769 rounds/min

Caliber of Bullet - 5.56×45mm NATO

Muzzle Velocity - 2,788.7 ft/s

Magazine Capacity - 30-round with a detachable box magazine or 100-round with a C-Mag drum magazine

Country of Origin - Germany

Special Features - This gun does not have a gas valve, therefore it uses a self-regulating spring-buffered short-stroke gas piston system.


L86A1 LSW

Type - Selective fire

Rate of Fire - 800 rounds/min

Caliber of Bullet - 5.56×45mm NATO

Muzzle Velocity - 3,182.4 ft/s

Magazine Capacity - 30-round detachable STANAG magazine

Country of Origin - United Kingdom

Special Features - This weapon was made, keeping the bullpup design in mind. The compactness of this weapon is achieved without shortening the barrel length.


Famas G2

Type - Selective fire

Rate of Fire - 1000-1100 rounds/min

Caliber of Bullet - 5.56×45mm NATO

Muzzle Velocity - 3,030 ft/s

Magazine Capacity - 30-round box magazine (STANAG)

Country of Origin - France

Special Features - This reliable and trustworthy weapon is one of the rare guns that use a delayed blowback action.


HK-416

Type - Selective fire

Rate of Fire - Cyclic 700-900 rounds/min

Caliber of Bullet - 5.56×45mm NATO

Muzzle Velocity - Varies by barrel length and type of round used.

Magazine Capacity - 20, 30-round STANAG magazine or 100-round Beta C-Mag

Country of Origin - Germany

Special Features - Short-stroke gas piston makes this gun suitable for use for long periods of time as there is no powder residue left after firing this gun.

Every country has different set of laws pertaining to guns, so make sure you have the appropriate paperwork or license before you acquire a gun. All assault rifles have different specifications, it is best to choose one that appeals to you the most. You must always remember that a gun is a killing machine, so handle it responsibly.
Read more at Buzzle: http://www.buzzle.com/articles/best-assault-rifle.html

Examples of Compounds

What are chemical compounds? What are they made up of? What are some examples of compounds? Scroll down for answers to these questions...

 

 

Chemical compounds are substances that are made up of atoms of two or more different elements. There are millions of known compounds formed from various elements that exist in nature. The elements combine in a fixed ratio to form a specific chemical compound, and the constituent atoms are held together by chemical bonds. The composition or the ratio in which the elements are present in the compound, plays a key role in determining the properties of the compound. The compounds are named according to the rules decided by the International Union of Pure and Applied Chemistry (IUPAC).

Classification of Chemical Compounds

Chemical compounds can be broadly classified into two categories, namely, organic compounds and inorganic compounds. While organic compounds are further classified on the basis of the functional group present, inorganic compounds are classified on the basis of the type of bonds between the constituent atoms. Here we shall look at some examples of compounds under each category.

 

Organic Compounds

Organic compounds are complex compounds of carbon in which one or more atoms of carbon are covalently linked to atoms of other elements, such as hydrogen, nitrogen, and oxygen. Hydrocarbons are organic compounds that are made up of carbon and hydrogen atoms only. When functional groups are attached to one or more carbon atoms of the hydrocarbon chain, then the chemical properties change. Organic compounds are classified on the basis of the functional group attached to the carbon atoms.

Hydrocarbons

Hydrocarbons are further classified into alkanes, alkenes, alkynes, and aromatic hydrocarbons. Let us see some examples of each.

Alkanes

R-H
Alkane
Alkanes are saturated hydrocarbons having single bonds between each pair of carbon atoms. The simplest alkane is methane, in which one carbon atom is linked with four atoms of hydrogen. Ethane comes next, and has two carbon atoms linked to each other by single covalent bonds. Alkanes are the least reactive hydrocarbons. The representation of alkanes is shown alongside. The general formula for alkanes is CnH2n+2, while the same for cyclic alkanes is CnH2n.

Examples

Propane (C3H8)
Butane (C4H10)
Pentane (C5H12)
Hexane (C6H14)
Cyclohexane (C6H12)

Cyclopentane (C5H10)
Decane (C10H22)
Isocane (C20H42)
Pentacontane (C50H102)
Hexacontane (C60H122)


Alkyl Group

Alkyl group
Alkyl Group
Alkyl refers to a substituent or functional group that is derived from an alkane. It is represented by R-. The simplest alkyl group is the methyl group (CH3), which is obtained by removing one hydrogen atom from methane (CH4). Since an alkyl group is obtained by removing one hydrogen atom from the parent alkane, the general formula for alkyl groups can be given as CnH2n+1.

Similarly, we can derive alkyl groups from ethane, propane, butane, pentane, hexane, etc. The names of a few alkyl groups are given below.

Examples

Ethyl group (C2H5) from ethane (C2H6)
Propyl group (C3H7) from Propane (C3H8)
Butyl group (C4H9) from Butane (C4H10)
Pentyl group (C5H11) from Pentane (C5H12)
Hexyl group (C6H13) from Hexane (C6H14)


Alkenes

C=C
Alkene
Alkenes are hydrocarbons having at least one C=C double bond. The simplest alkene is ethene, in which two carbon atoms are linked with a double covalent bond. Alkenes exhibit cis-trans isomerism, and are more reactive than alkanes. The general formula for alkenes with a single double-bond is CnH2n, while the same for cyclic alkenes is CnH2n-2. Alkenes with more than one double bond, are known as polyenes.

Examples

Propene (C3H6)
Butene (C4H8)
Pentene (C5H10)
Hexene (C6H12)
Heptene (C7H14)

Octene (C8H16)
Cyclopentene (C5H8)
Cyclohexene (C6H10)
2-Methylpropene (C4H8)
2-Methyl-2-hexene (C7H14)


Alkynes

C≡C
Alkyne
Alkynes are hydrocarbons having at least one C≡C triple bond. The simplest alkyne is ethyne, in which two carbon atoms are linked with a triple covalent bond. Alkynes are the most reactive hydrocarbons. The general formula for alkynes is CnH2n-2, while the same for cyclic alkynes is CnH2n-4.

Examples

Propyne (C3H4)
Butyne (C4H6)
4-methyl-2-pentyne (C6H10)
4-methyl-1-pentyne (C6H10)
1-pentyne (C5H8)

Cyclooctyne (C8H12)
1-hexyne (C6H10)
1-heptyne (C7H12)
1-decyne (C10H18)
5-cyclopropyl-1-pentyne (C8H12)


Aromatic Hydrocarbons

Benzene
Benzene
Also known as arenes, aromatic hydrocarbons are characterized by a six-carbon ring that has alternate C=C double bonds, separated by C-C single bonds. They are known as aromatic hydrocarbons because most of these compounds have a sweet scent. Benzene is the simplest of these compounds. There are two types of aromatic hydrocarbons: monocyclic aromatic hydrocarbons (MAH) and polycyclic aromatic hydrocarbons (PAH).

Examples

Methylbenzene or Toluene (C7H8)
Styrene (C8H8)
Trimethylbenzene (C9H12)
Azulene (C10H8)
Anthracene (C14H10)

2-Phenylhexane (C12H18)
Durene (C10H14)
1,3,5-trimethylbenzene (C9H12)
m-Xylene (C8H10)
Ethylbenzene (C8H10)


Aryl Group

Aryl group
Aryl Group
Aryl refers to a substituent or functional group that is derived from an aromatic ring. It is represented by Ar. The simplest aryl group is the phenyl group (C6H5), which is obtained by removing one hydrogen atom from the benzene (C6H6) ring.

Similarly, we can derive aryl groups from naphthalene, thiophene, durene, xylene, toluene, etc. The names of the aryl groups derived from toluene and xylene, are given below.

Examples

Tolyl [CH3C6H4] from toluene [CH3C6H5]
Xylyl [(CH3)2C6H3] from xylene [(CH3)2C6H4]

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Organic Compounds Containing Oxygen

There are many functional groups that contain one or more oxygen atoms. Given below is a list of such functional groups, along with examples of compounds under each.

Hydroxyl Group

Hydroxyl group
Hydroxyl Group
The hydroxyl group is a functional group that consists of a hydrogen atom and an oxygen atom, linked together by a covalent bond. The anion (OH-) is the hydroxide anion, in which the negative charge resides on the oxygen atom. The hydroxyl radical (HO) is the neutral form of the hydroxyl group. In organic chemistry, the hydroxyl group is the defining functional group in alcohols. The general formula for acyclic alcohols is CnH2n+1OH.

Now, let us have a look at some examples of organic compounds with the hydroxyl group.

Examples

Methanol (CH4O)
Ethanol (C2H6O)
Propanol (C3H8O)
Butanol (C4H10O)
Pentanol (C5H12O)
Hexanol (C6H14O)

Ethylene glycol (C2H6O2)
Glycerol (C3H8O3)
Xylitol (C5H12O5)
Allyl alcohol (C3H6O)
Volemitol (C7H16O7)
Inositol (C6H12O6)


Ethers

Ether group
Ether
Ethers are organic compounds that contain the ether group, which is identified as two alkyl or aryl groups connected by an oxygen atom. The general formula of ethers is R-O-R'. Depending on whether the alkyl or aryl groups on both sides of the oxygen atom, are similar or different, ethers are classified as simple (symmetrical) and mixed (asymmetrical). In simple ethers, both R and R' are the same, while in mixed ethers, R and R' are different alkyl or aryl groups. The simplest ether is dimethyl ether, in which two methyl groups are connected to an oxygen atom.

Examples

Methoxymethane or dimethyl ether (C2H6O)
Ethoxyethane or diethyl ether (C4H10O)
Oxolane or tetrahydrofuran (C4H8O)
1,4-Dioxane (C4H8O2)
Polyethylene glycol (C2nH4n+2On+1)

Methoxybenzene or anisole (C7H8O)
1,2-Dimethoxyethane (C4H10O2)
Oxirane or ethylene oxide (C2H4O)
Methylheptyl ether (C8H18O)
Methoxybenzene or anisole (C7H8O)


Aldehydes

Aldehyde
Aldehyde
An organic compound that contains a formyl group, is known as an aldehyde. The presence of a carbonyl center that is linked to a hydrogen atom on one side, and an R- group on the other, is what defines an aldehyde. The carbonyl center is a carbon atom that is linked to an oxygen atom by double covalent bonds. The general formula for aldehydes is R-CHO, where -CHO is the formyl group. Organic compounds that have two aldehyde groups are known as dialdehydes. An example of a dialdehyde is glyoxal.

Examples

Methanal or formaldehyde (CH2O)
Ethanal or acetaldehyde (C2H4O)
Benzaldehyde (C7H6O)
Tolualdehyde (C8H8O)
Butanal (C4H8O)

Retinaldehyde (C20H28O)
Cinnamaldehyde (C9H8O)
Furan-2-carbaldehyde or furfural (C5H4O2)
Ethanedial or glyoxal (C2H2O2)
Propanedial or malondialdehyde (C3H4O2)


Ketones

Ketone
Ketone
Ketones are a group of organic compounds that contain the carbonyl group bonded to two other carbon atoms. The general formula of ketones is RC(=O)R', where R and R' can be alkyl or aryl groups. The simplest ketone is propanone (C3H6O), commonly known as acetone. Ketones with one or more alpha-hydrogen atoms (hydrogen atom attached to the alpha carbon), exhibit a phenomenon known as the keto-enol tautomerism. Ketones are also classified as symmetrical and asymmetrical ketones, depending on the nature of the alkyl and aryl groups present.

Examples

Butenone or methyl vinyl ketone (C4H6O)
Propanone or acetone (C3H6O)
Butanone (C4H8O)
Cyclopropanone (C3H4O)
1-Phenylethanone or acetophenone (C8H8O)

Diphenyl methanone (C13H10O)
3-Methylcyclopentanone (C6H10O)
6-Undecanone (C11H22O)
4-Tetradecanone (C14H28O)
4,4-Dimethyl-2-pentanone (C7H14O)


Carboxylic Acids

Carboxylic Acid
Carboxylic Acid
Carboxylic acids are organic compounds with at least one carboxyl group. The carboxyl group consists of a carbonyl group (RR'C=O), and a hydroxyl group (R-O-H). It is represented as -COOH. The general formula for carboxylic acids is R-COOH. These are the most commonly occurring acids in organic chemistry. However, carboxylic acids are weak acids with strong odors.

The simplest member of this group is methanoic acid, which is also known as formic acid.

Examples

Formic acid or methanoic acid (CH2O2)
Acetic acid or ethanoic acid (C2H4O2)
Butanoic acid (C4H8O2)
Pentanoic acid or valeric acid (C5H10O2)
Decanoic acid or capric acid (C10H20O2)

Dodecanoic acid or lauric acid (C12H24O2)
Octadecanoic acid or stearic acid (C18H36O2)
Hexadecanoic acid or palmitic acid (C16H32O2)
Benzoic acid (C7H6O2)
Toluic acid (C8H8O2)


Acid Chlorides

Acid Chloride
Acid Chloride
Acid chlorides are organic compounds that contain the functional group -CO-Cl in their structure. They are derived from carboxylic acids. The general formula for acid chlorides is RCOCl. The simplest acid chloride is acetyl chloride (CH3COCl). Similarly, carboxylic acids can also react to form acid halides (bromides, iodides, etc). Acid chlorides are also known as acyl chlorides, and are highly reactive. They are used in the synthesis of acid anhydrides, esters, and amides.

Examples

Acetyl chloride (C2H3ClO)
Benzoyl chloride (C7H5ClO)
Propanoyl chloride (C3H5ClO)
Butanoyl chloride (C4H7ClO)
2-Methylpropanoyl chloride (C4H7ClO)

Fluoroacetyl chloride (C2H2ClFO)
Acryloyl chloride (C3H3ClO)
Adipoyl chloride (C6H8Cl2O2)
Anisoyl chloride (C8H7ClO2)
Oxalyl dichloride (C2O2Cl2)


Esters

Ester
Ester
In inorganic chemistry, alkalis react with acids to form salts. Similarly, in organic chemistry, hydroxyl compounds (alcohols and phenols) react with oxoacids (acids that contain oxygen) to form esters. Thus, esters are nothing but salts of alcohols and acids. The most common esters are those derived from carboxylic acids. The process by which carboxylic acids react with alcohols in the presence of hydrochloric or sulfuric acids, is termed as esterification. The reaction involves the replacement of the hydroxyl (OH) group of the acid with the alkoxy (R'O) group of the alcohol. Esters can also be formed from acid anhydrides, acyl chlorides, carboxylate salts, and other esters.

Examples

Butyl butanoate (C8H16O2)
Ethyl acetate (C4H8O2)
Ethyl formate (C3H6O2)
Isopropyl acetate (C5H10O2)
Isobutyl acetate (C6H12O2)

Methyl benzoate (C8H8O2)
Methyl pentanoate (C6H12O2)
Ethyl pentanoate (C7H14O2)
Benzyl acetate (C9H10O2)
Ethyl hexanoate (C8H16O2)

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Compounds Containing Nitrogen

These are compounds with a functional group that has nitrogen atoms in it, which includes amines, amides, and nitriles.

Amines

Amine
Amine
Amines are organic compounds that are derivatives of ammonia (NH3), in which the hydrogen atoms of ammonia have been replaced by alkyl or aryl groups. Amines can be identified by the presence of a nitrogen atom with a lone pair of electrons. Amines that have an aromatic ring attached to the nitrogen atom are known as aromatic amines, while others are known as aliphatic amines. All amines are more basic, when compared to ammonia. Amines can be categorized into three classes, and these are as follows:

Primary Amines
In primary amines, one of the three hydrogen atoms in ammonia, is replaced by an alkyl or aryl group. Thus, primary amines can be aliphatic or aromatic. The general chemical formula for primary amines is RNH2, and they are named as "alkylamine". Examples of aliphatic primary amines are methylamine, ethylamine, and propylamine, while an example of aromatic primary amines is phenylamine (aniline).

Secondary Amines
In secondary amines, two of the three hydrogen atoms in ammonia, are replaced by alkyl or aryl groups. The general formula for secondary amines is R2NH, and they are named as "dialkylamine". Secondary amines can be cyclic. Examples of secondary aliphatic amines are dimethylamine, ethylmethylamine, and diethylamine, while an example of secondary aromatic amines is diphenylamine.

Tertiary Amines
In tertiary amines, all the three hydrogen atoms of ammonia, are replaced by alkyl or aryl groups. In other words, a tertiary amine has three hydrocarbon groups attached to the nitrogen atom. Tertiary amines can be cyclic. The general formula for tertiary amines is R3N, and they are named as "trialkylamine". Examples are trimethylamine and triphenylamine.

If all four hydrogen atoms of an ammonium ion are replaced with alkyl or aryl groups, then a quaternary ammonium salt is formed, which is ionic. The simplest example of such a salt is tetramethylammonium chloride (CH3)4N+ Cl-. Given below are a few examples of primary, secondary, and tertiary amines.

Examples

Propylamine (C3H9N)
Butylamine (C4H11N)
Pentylamine (C5H13N)
Phenylamine or aniline (C6H7N)
Dimethylamine (C2H7N)

Diethylamine (C4H11N)
Methylpropylamine (C4H11N)
Diphenylamine (C12H11N)
Trimethylamine (C3H9N)
Triphenylamine (C18H15N)


Amides

Amide Group
Amide
Amides or acid amides are carboxylic acid (RCOOH) derivatives, in which the -OH part of the acid is replaced by -NH2 group. The general formula for organic amides is RCONH2. Amides are further classified into primary, secondary and tertiary amides, based on the number of hydrogen atoms attached to the nitrogen atom of the functional group -CONH2. Given below are a few examples of amides.

Examples

Methanamide (CH3NO)
Ethanamide (C2H5NO)
Propanamide (C3H7NO)
Pentanamide (C5H9NO)
Benzamide (C7H7NO)

N-methylethanamide (C3H7NO)
N-phenylethanamide (C8H9NO)
N-phenylbenzamide (C13H11NO)
N,N-dimethylethanamide (C4H9NO)
N,N-dimethylbenzamide (C9H11NO)


Nitriles:

Nitrile Group
Nitrile
Any organic compound that has a -C≡N functional group, is a nitrile. The term cyano is also used as a substituent prefix for nitriles. The general chemical formula for nitriles is RC≡N. Inorganic compounds that have the -C≡N group are known as cyanides. Nitriles are synthesized from hydrocarbons, cyanide salts, organic halides, amides, and oximes. The nomenclature of nitriles is on the basis of the number of carbon atoms in the longest carbon chain, including the carbon atom of the -C≡N group. Examples of simple nitriles are ethanenitrile, propanenitrile, and butanenitrile. Given below are a few examples of nitriles.

Examples

Acetonitrile (C2H3N)
Propanenitrile (C3H5N)
Butanenitrile (C4H7N)
Pentanenitrile (C5H9N)
Hexanenitrile (C6H11N)

2-Propenenitrile (C3H3N)
Cyclobutyronitrile (C5H7N)
Benzonitrile (C7H5N)
Pentanedinitrile (C5H6N2)
Adiponitrile (C6H8N2)

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Inorganic Compounds

Inorganic compounds are compounds that do not contain carbon. However, there are exceptions, which include compounds such as carbon dioxide, carbon monoxide, etc. Inorganic compounds can be classified into ionic compounds, molecular compounds, and aqueous acids.

Ionic Compounds

Ionic compounds are compounds that contain one metal ion and one or more non-metal ions. Ionic compounds can be binary or ternary, and these two types are explained below, along with examples for each.

Binary Ionic Compounds
Ionic compounds that contain two elements, of which one is a metal and the other is a non-metal, are known as binary ionic compounds. One example of such a compound is sodium chloride (NaCl), which contains one sodium ion (metal) and one chloride ion (non-metal). More examples of binary ionic compounds are given below.

Lithium Fluoride (LiF)
Lithium Bromide (LiBr)
Lithium Selenide (Li2Se)
Lithium Nitride (Li3N)
Sodium Chloride (NaCl)

Cesium Fluoride (CsF)
Beryllium Sulfide (BeS)
Magnesium Fluoride (MgF2)
Magnesium Chloride (MgCl2)
Calcium Bromide (CaBr2)


Ternary Ionic Compounds
Ionic compounds that contain three elements, which consist of at least one metal and one non-metal, are known as ternary ionic compounds. One example of such a compound is calcium carbonate (CaCO3), which has one calcium ion (metal), one carbon ion (non-metal), and three oxygen ions. More examples of ternary ionic compounds are given below.

Examples

Lithium Hydroxide (LiH)
Sodium Nitrate (NaNO3)
Sodium Chlorate (NaClO3)
Silver Peroxide (Ag2O2)
Magnesium Carbonate (MgCO3)

Silver Hydroxide (AgOH)
Silver Nitrate (AgNO3)
Beryllium Sulfate (BeSO4)
Cesium Hydroxide (CsOH)
Magnesium Sulfate (MgSO4)

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Molecular Compounds

Molecular compounds are compounds in which two or more non-metal atoms form a molecule. These are also known as covalent compounds because the bonds between the atoms in the molecule are covalent bonds. Molecular compounds may be polar or non-polar, depending on the shape of the molecule, and the polarity of the bonds formed between the constituent atoms. Here are some examples of molecular compounds.

Examples

Sulfur Dichloride (SCl2)
Silicon tetrafluoride (SiF4)
Water (H2O)
Ammonia (NH3)
Sulfur dibromide (SBr2)

Boron trifluoride (BF3)
Carbon tetrabromide (CBr4)
Disulfur diiodide (SI)
Phosphorous trihydride (PH3)
Silicon dioxide (SiO2)

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Aqueous Acids

The term aqueous is used for the solution of a substance in water. Thus, aqueous acids are acids in solution with water. These acids are either binary acids or ternary acids. Let's have a look at the examples of each.

Binary Acids
Binary acids contain two elements, of which one is hydrogen, and the other one is a non-metal. One example is hydrochloric acid (HCl), which contains one hydrogen atom and one chlorine atom (non-metal). More examples of binary aqueous acids are given below.

Examples

Hydrofluoric acid (HF)
Hydrobromic acid (HBr)
Hydroiodic acid (HI)
Hydrosulfuric acid (H2S)
Hydroselenic acid (H2Se)

Hydroarsenic acid (H3As)
Hydrocarbonic acid (H4C)
Hydrosiliconic acid (H4Si)
Hydronitric acid (H3N)
Hydrophosphoric acid (H3P)


Ternary Acids
Ternary acids contain three elements, of which one is hydrogen, one is oxygen, and the third element is a non-metal. One example is sulfuric acid (H2SO4), which contains hydrogen, sulfur (non-metal), and oxygen. More examples of ternary aqueous acids are given below.

Examples

Nitric acid (HNO3)
Phosphoric acid (H3PO4)
Boric acid (H3BO3)
Carbonic acid (H2CO3)
Nitrous acid (HNO2)

Permanganic acid (HMnO4)
Arsenic acid (H3AsO4)
Arsenous acid (H3AsO3)
Hypochlorous acid (HClO)
Perchloric acid (HClO4)


These were some examples of compounds in chemistry. There are millions of chemical compounds out there and hence, it is a difficult to enlist all of them here. However, most of the compounds mentioned above, have wide applications in different areas.

Potential Energy Formula

What is the potential energy formula for a gravitational field, a spring or an electric field? How is potential energy defined? Answer to all these questions and more are provided here, along with ready-to-use potential energy calculators.

 

 

Gravitational Potential Energy = mgh

where m is the mass, g is the acceleration due to gravity (9.8 m/s2) and h is the height above Earth surface.

 

Energy is the most fundamental concept in physics. Whatever be the operating force (electromagnetic, gravitational, strong or weak), every change that occurs in the universe is a conversion from potential to kinetic energy. From merely being in a position in space, in presence of forces, a particle has an inherent energy associated with it, that's termed as potential energy. Depending on the force involved, the associated potential energy formulas vary. For a detailed explanation of potential energy, scroll down further. In what follows, the most commonly used formulas are presented, along with calculators.

Potential Energy Formulas

 

The formula for potential energy of a system depends on the forces at work and the constituents of a system. All macroscopic systems outside the atomic nucleus are either governed by the electromagnetic or gravitational forces. Potential energy is measured in SI unit of 'Joule'.

Gravitational potential energy is a function of the position of the object in a gravitational field, force of gravity at that point and mass of the object. The formula is as follows:

What is Potential Energy?

Potential energy is the dormant stored energy in any system. It is a type of energy that a system possesses on account of its configuration and position of various constituents of that system in presence of a force. It is the energy stored in an object when work is done against a force. Depending on the configuration of a system and the forces operational in it, there are various forms of potential energy. Motion occurs when this stored energy is converted into kinetic energy.

The formula for potential energy of an object in a force field depends on its position and other inherent factors like mass and charge. For example, when an object is lifted up, work is done against the gravitational force (that pulls it down). This work done on the object is stored as potential energy. When such an object is released from the height to which it has been lifted and it falls freely, gravitational potential energy gets converted into kinetic energy. So one can say that objects at higher altitudes on Earth have a higher potential energy.

The knowledge of potential energy of a system at a point is a useful result, but what we ultimately want is an equation that predicts the position of a particle at any moment of time, along with its energy. To get that, is to derive the equation of motion of a system. There are various ways of deriving it. One of them is through solution of Lagrangian equations of motion. The Lagrangian is the difference of potential and kinetic energy of a system. You need to know the potential energy formulas for particular systems along with the kinetic energy expressions, to set up the Lagrangian. Ergo, to understand potential energy and its computation is just the first step in your journey into classical mechanics.

How to Clean an EGR Valve

If you are on the look out for instructions detailing the EGR valve cleanup of your car, this article can offer some help in that matter. By scheduling periodic maintenance of the valve, you can achieve the twin objectives of reduction in emission and optimization of engine efficiency.

Controlling emission of polluting gases from a car exhaust was a major challenge for automobile designers. A technological breakthrough that achieved this purpose was the EGR (Exhaust Gas Recirculation) mechanism fixed in car engines. Automobile technology constantly evolves to provide better solutions. The EGR valve cleaning instructions provided further will apply to most automobiles but not necessarily all of them, considering the differences in design approach of various manufacturers.

EGR Valve Cleaning Instructions
The EGR valve can cause a fall in engine efficiency and seriously compromise fuel economy of a car, due to carbon deposition and blocking caused by particulate matter. Clogging can cause the diaphragm inside the valve to fall into disrepair. The valve is supposed to close and open during an engine cycle to release exhaust gases in a feedback loop, to keep the engine temperature down. If the valve becomes unresponsive and stays open or closed, the engine pings or knocks, driving down efficiency. That necessitates valve cleaning once a year. Here is a short guide. You will require a wrench set, socket set, scratch awl, cleaning brush, ratchet, carburetor cleaning fluid, a vacuum pump (optional) and Phillips screwdriver for the job. It's recommended that you wear safety glasses and gloves for protection.

Step 1: Disconnect the car battery's negative terminal. Open the car hood and locate the EGR valve. It usually lies on the engine side and has a vacuum hose on top and an electrical connector. Refer your car manual for the exact location.

Step 2: Remove the vacuum line attached to the EGR valve, along with the electrical connector. If on observation, the vacuum hose appears to be worn out or damaged, it should be replaced immediately. You will also have to remove the pipe that connects to the valve bottom. With all these connections removed, the valve itself can now be removed for inspection and cleaning.

Step 3: Remove the entire valve assembly by unscrewing the nuts holding it to the engine and the gasket, using wrenches. Now you can work on the valve.

Step 4: Disconnect the solenoid that's usually attached at the valve top, with a screwdriver.

Step 5: With the help of a scratch awl, clean the bottom passage of the valve mechanism. This will get rid of the carbon deposits inside. If there are no electronic connections associated with the valve, you may soak the entire valve body in a cleaning fluid. However, in case you have an electronic valve, soaking is forbidden. Spray the carburetor cleaning fluid on the valve, barring the electrical connections. Using a brush, clean every accessible surface of the valve body.

Step 6: Also clean the pipe attached to the bottom passage. In case the valve gasket is damaged, replace it. Otherwise just clean it and you are done. Let the valve dry. Vacuuming it will remove fine particulate matter, besides helping it dry quickly.

Step 7: With that, you have finished cleaning the valve. Rest of the job is putting it back as it was. To do this, you must retrace your steps and go in reverse, by connecting the solenoid, pipe, vacuum hose, electrical connector and then reattach the valve in its place in the proper reverse order. With that, your cleaning job is finished entirely. Reconnect the car battery and you are good to go.

For those of you looking for a deeper understanding of the exact function of the EGR valve, a short introduction is provided in rest of the article.

About EGR Valves
The concept of 'Exhaust Gas Recirculation' evolved out of the need to restrain the emission of nitrogen oxide compounds from a car's exhaust. Besides causing smog, these compounds are poisonous gases that cause adverse effects in many biological systems that come in contact with them. Smog reduces visibility. That's why reduction of their emission through the exhaust was a high priority task. Nitrous oxide is copiously produced in high temperature conditions inside an engine, in a high concentration mixture of nitrogen and oxygen. Automobile engineers developed the valve mechanism to nip the problem of nitrogen oxide production in the bud.

This was achieved in the following manner using a feedback mechanism. A portion of the exhaust gases are fed back to the engine's combustion chambers. This causes a drop in the temperature of the gasoline-air mixture and reduces the production of nitrogen oxide compounds. The valve's function is to control when and how this feedback is supplied to the engine. The exhaust gases are not fed back when the engine is in high RPM mode or when it is almost idling. This ensures that the car engine's efficiency is not compromised. Thus the valve's functioning is crucial for maintenance of engine efficiency.

A clean up job of an EGR valve, with a repair center will cost about $100 to $200. It is recommended that the valve be examined after every 13,000 miles of running. In your yearly car maintenance campaign, make sure that the EGR valve cleanup is included.