Draw an electron dot structure of the following molecules. (Without showing the circles)
Draw all possible structural formulae of compounds from their molecular formula given below.
Explain the following terms with example.
a. Structural isomerism
b. Covalent bond
c. Hetero atom in a carbon compound
d. Functional group
f. Unsaturated hydrocarbon
a. Structural isomerism: -Structural isomerism or constitutional isomerism is a form of isomerism in which molecules have same molecular formula but different arrangements of the atoms in space.
Different arrangement may be in bonding patterns and atomic organization.
For example: CH3OCH3 and CH3CH2OH are structural isomers.
b. Covalent bond: -Covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.
These electron pairs are known as shared pairs or bonding pairs.
It is also known as molecular bond.
For example: Molecules that have covalent linkages are hydrogen, nitrogen, chlorine, water, and ammonia (H2, N2, Cl2, H2O, NH3).
A single line indicates a single bond between two atoms (i.e.involving one electron pair), double lines (=) indicate a double bond between two atoms (i.e. involving two electron pairs), and triple lines (≡) represent a triple bond (C≡O).
c. Hetero atom in a carbon compound: It is a compound formed by replacement of carbon and hydrogen by heteroatom in a compound.
A heteroatom is any atom other than carbon or hydrogen.
Typical heteroatoms are nitrogen, oxygen, sulfur, phosphorus, chlorine, bromine, and iodine.
Similarly, Nitrogen is the hetero atom in Ethyl amine ( CH3-CH2–NH2)
d. Functional group: The functional group is defined as an atom or group of atoms joined in a specific manner, which gives the chemical properties of the organic compound and they are the centers for chemical reactivity.
Compounds having a similar functional group undergoes similar reactions.
1. Alkane: The functional group presence in the alkane is -C-C-. The IUPAC group suffix of an alkane is –ane.
Example: Methane CH4
2. Alkene: The functional group presence in the alkene is -C=C- (double bond). The IUPAC group suffix of an alkene is –ene.
3. Alkynes: The functional group presence in the alkyne is -C ≡ C- (triple bond). The IUPAC group suffix of an alkyne is –yne.
4. Arenes: They contain a benzene ring as the functional group.
5. Halides: The functional group presence in halides is X(halogen).
6. Alcohols: The functional group, which is present in alcohol, is -OH. The IUPAC group suffix of alcohol is –ol.
7. Aldehydes: The functional group, which is present in an aldehyde, is -CHO. The IUPAC group suffix of an aldehyde is –al.
8. Ketones: The functional group, which is present in a ketone is >C=O. The IUPAC group suffix of a ketone is –one. Example: Acetone
9. Carboxylic acid: The functional group present in a carboxylic acid is -COOH. The IUPAC group suffix of a carboxylic acid is –oic acid.
Example: Acetic acid
10. Amine: The functional groups present in an amine are -NH2>NH>N- The IUPAC group prefix of an amine is amino– or the suffix is –amine. Example: Methylamine
11. Ester: The functional group present in an ester is -COOR The IUPAC group suffix of an ester is –ate. Example: Ethyl acetate
e. Alkane: Alkane is a saturated hydrocarbon.
It is formed when there is sharing of one electron pair between carbon atoms in a compound.
The general formula for alkane is CNH2N+2, where N is equal to no of carbon atoms in a compound.
f. Unsaturated hydrocarbon:An unsaturated hydrocarbon is a hydrocarbon containing at least one double or triple bond.
For example: Alkenes – These unsaturated hydrocarbons are molecules that contain at least one carbon-to-carbon double bond.
With the chemical formula consisting of CnH2n.
The simplest alkene is ethylene.
Alkynes – These unsaturated hydrocarbons are molecules that contain at least one carbon-to-carbon triple bond.
Acetylenes are common examples of alkynes.
g. Homopolymer: A homopolymer is a polymer formed from the same type of monomer units.
Polystyrene are homopolymer.
h. Monomer:A monomer is a molecule that forms the basic unit for polymers.
They may be considered as building blocks from which proteins are made.
Monomers may bind to other monomer unit to form a repeating chain molecule.
Monomers may be either natural or synthetic in origin.
i. Reduction:The addition of hydrogen to a substance is called reduction.
The removal of oxygen from a substance is called reduction.
For example:2Ag2O → 4 Ag + O2 ↑ In a reaction, silver oxide is changing to silver.
That is, oxygen is being removed from silver oxide.
Removal of oxygen from a substance is called reduction, so silver oxide undergoes reduction.
NiO + H2 → Ni + H2O In a reaction, Nickel oxide is changing to nickel.
That is, oxygen is being removed from nickel oxide.
Removal of oxygen from a substance is called reduction, so nickel oxide undergoes reduction.
In a reaction, hydrogen is changing to H2O.
That is, oxygen is being added to hydrogen.
Addition of oxygen to a substance is called oxidation, so hydrogen undergoes oxidation.
j. Oxidant:– The substance which gives oxygen for oxidation is called an oxidizing agent or oxidant.
The substance which removes hydrogen is called an oxidizing agent or oxidant.