First Term

Question 1

Chemistry

Answer 1

Chemistry is the branch of science dealing with the structure, composition, properties and reactive characteristics of matter. Moreover chemistry is the study of transformation of matter.

Question 2

Importance of chemistry

Answer 2

Chemistry is a big part of our life. It is important in medicine, food, in our body, the air we breath, etc.

Question 3

Branches of chemistry

Answer 3

1) physical chemistry: The study of physical properties like state, odour, solubility, color, kinetics, heat, viscosity,etc.

2) organic chemistry: The study of hydrocarbons and their derivatives.

3) Inorganic chemistry: The study of elements and their compound.

4) Analytical chemistry: The study of instruments and method to separate, identify and quantifying.

5) Bio chemistry: Explore the chemical process within and related to living organisms.

Question 4

Hydrocarbon

Answer 4

Organic compounds in which carbon atoms are joined to hydrogen by covalent bond.

Question 5

Derivatives

Answer 5

All other compounds which are derived from hydrocarbons are derivatives. Ex:- CH3CN, CH3OH, CH3COOH, CH3NH2, etc.

Question 6

Tetracovalency of carbon

Answer 6

The electronic configuration of carbon atom is 2, 4. It avails 4 valence electrons. The four valence electron of carbon prefer sharing with other four electron of the next atom to form covalent bonds. This property of carbon atom by virtue of which forms four covalent bond is referred as tetracovalency.

Question 7

Catenation

Answer 7

The property of self-linking with atom of same element termed as catenation. Carbon has unit property of linking itself to other carbon atom to give open chain, branched chain and cyclic structure.

Question 8

Empirical formula

Answer 8

Empirical formula of a compound is simplest formula whose expressed the ratio of different element present in molecules.

Question 9

Molecular formula

Answer 9

The formula expressing the actual number of atoms of various elements present in molecule of compound is called molecular formula.

Question 10

Structural formula

Answer 10

Formula which gives a complete picture to how the various atoms are bonded to each other in the molecules is known as structural formula.

Question 11

Contracted formula

Answer 11

It gives the arrangement of atoms in a molecule as given by structure formula in condensed form.