The Ministry of Education and science

Donetsk National University

Report

Examples of Chemical Compounds

(Примеры химических соединений)

Submitted by

Irina Galutskaya

1-st year student

The department of chemistry

Language adviser

L.V.Sulina

Donetsk

2013

Examples of Chemical Compounds

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.

Types of Chemical Compounds

Organic Compounds

• Hydrocarbons

• Compounds Containing Oxygen

• Compounds Containing Nitrogen

Inorganic Compounds

• Ionic compounds

• Molecular compounds

• Aqueous acids

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

H

R-H

Alkane

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

Alkanes

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 CnH_2n+2, while the same for cyclic alkanes is CnH_2n.

Examples

• Propane (C₃H₈) • Cyclohexane (C₆H₁₂)

• Butane (C₄H₁₀) • Cyclopentane (C₅H₁₀)

• Pentane (C₅H₁₂) • Decane (C₁₀H₂₂)

A

C=C

Alkene

lkenes

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 exhibitcis-trans isomerism, and are more reactive than alkanes. The general formula for alkenes with a single double-bond is CnH_2n, while the same for cyclic alkenes is CnH_2n-2. Alkenes with more than one double bond, are known as polyenes.

Examples

• Propene (C₃H₆) • Octene (C₈H₁₆)

• Butene (C₄H₈) • Cyclopentene (C₅H₈)

• Pentene (C₅H₁₀) • Cyclohexene (C₆H₁₀)

• Hexene (C₆H₁₂) • 2-Methylpropene (C₄H₈)

•

C≡C

Alkyne

Heptene (C₇H₁₄) • 2-Methyl-2-hexene (C₇H₁₄)

Alkynes

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 CnH_2n-2, while the same for cyclic alkynes is CnH_2n-4.

Examples

• Propyne (C₃H₄) • Cyclooctyne (C₈H₁₂)

• Butyne (C₄H₆) • 1-hexyne (C₆H₁₀)

• 4-methyl-2-pentyne (C₆H₁₀) • 1-heptyne (C₇H₁₂)

• 4-methyl-1-pentyne (C₆H₁₀) • 1-decyne (C₁₀H₁₈)

• 1-pentyne (C₅H₈) • 5-cyclopropyl-1-pentyne (C₈H₁₂)

Aromatic Hydrocarbons

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 aromatichydrocarbons 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) • 1,3,5-trimethylbenzene (C₉H₁₂)

• Styrene (C₈H₈) • Ethylbenzene (C₈H₁₀)

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

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 CnH_2n+1OH.

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

Examples

• Methanol (CH₄O) • Butanol (C₄H₁₀O)

• Ethanol (C₂H₆O) • Pentanol (C₅H₁₂O)

• Propanol (C₃H₈O) • Hexanol (C₆H₁₄O)

Ethers

E thers 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) • 1,4-Dioxane (C₄H₈O₂)

• Ethoxyethane or diethyl ether (C₄H₁₀O) • Polyethylene glycol (C_2nH_4n+2On+1)

• Oxolane or tetrahydrofuran (C₄H₈O)

Aldehydes

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)

Carboxylic Acids

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) • Pentanoic acid or valeric acid (C₅H₁₀O₂)

• Acetic acid or ethanoic acid (C₂H₄O₂) • Butanoic acid (C₄H₈O₂)

• Benzoic acid (C₇H₆O₂) • Toluic acid (C₈H₈O₂)

Esters

I n 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) • Methyl benzoate (C₈H₈O₂)

• Ethyl acetate (C₄H₈O₂) • Methyl pentanoate (C₆H₁₂O₂)

• Ethyl formate (C₃H₆O₂) • Ethyl pentanoate (C₇H₁₄O₂)

• Isopropyl acetate (C₅H₁₀O₂) • Benzyl acetate (C₉H₁₀O₂)

• Isobutyl acetate (C₆H₁₂O₂) • Ethyl hexanoate (C₈H₁₆O₂)

Compounds Containing Nitrogen

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

Amines

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) • Diethylamine (C₄H₁₁N)

• Butylamine (C₄H₁₁N) • Methylpropylamine (C₄H₁₁N)

• Pentylamine (C₅H₁₃N) • Diphenylamine (C₁₂H₁₁N)

• Phenylamine or aniline (C₆H₇N) • Trimethylamine (C₃H₉N)

• Dimethylamine (C₂H₇N) • Triphenylamine (C₁₈H₁₅N)

Amides

A mides 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)

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)  • Cesium Fluoride (CsF)

• Lithium Bromide (LiBr) • Beryllium Sulfide (BeS)

• Lithium Selenide (Li₂Se) • Magnesium Fluoride (MgF₂)

• Lithium Nitride (Li₃N) • Magnesium Chloride (MgCl₂)

• Sodium Chloride (NaCl) • 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) • Silver Hydroxide (AgOH)

• Sodium Nitrate (NaNO₃) • Silver Nitrate (AgNO₃)

• Sodium Chlorate (NaClO₃) • Beryllium Sulfate (BeSO₄)

• Silver Peroxide (Ag₂O₂) • Cesium Hydroxide (CsOH)

• Magnesium Carbonate (MgCO₃) • Magnesium Sulfate (MgSO₄)

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) • Boron trifluoride (BF₃)

• Silicon tetrafluoride (SiF₄) • Carbon tetrabromide (CBr₄)

• Water (H₂O) • Ammonia (NH₃)

• Sulfur dibromide (SBr₂) • Silicon dioxide (SiO₂)

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)

• Hydrocarbonic acid (H₄C) • Hydroiodic acid (HI)

• Hydrosulfuric acid (H₂S)

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) • Permanganic acid (HMnO₄)

• Phosphoric acid (H3PO₄) • Arsenic acid (H₃AsO₄)

• Boric acid (H₃BO₃) • Arsenous acid (H₃AsO₃)

• Carbonic acid (H₂CO₃) • Hypochlorous acid (HClO)

• Nitrous acid (HNO₂) • 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.