English Medium Class 9 - CBSE Question Bank Solutions

Discuss how water is replenished in sea

Define 'molecular mass' of a substance.

What is meant by saying that ‘the molecular mass of oxygen is 32’ ?

What is the significance of the formula H₂O ?

The molecular formula of glucose is C6H12O6. Calculate its molecular mass. (Atomic masses : C = 12 u ; H = 1 u ; O = 16 u)

Calculate the molecular masses of the following :

1. Hydrogen, H₂

(Atomic masses : H = 1 u ; O = 16 u ; Cl = 35.5 u ; N = 14 u ; C = 12 u)

Calculate the molecular masses of the following compounds :

Methanol, CH3OH

Calculate the molecular mass of ethanoic acid, CH₃COOH.

(Atomic masses: C = 12 u; H = 1 u; O = 16 u)

Calculate the molecular mass of nitric acid, HNO₃. (Atomic masses : H = 1 u ; N = 14 u ; O = 16 u)

Calculate the molecular mass of chloroform (CHCl3). (Atomic masses : C = 12 u ; H = 1 u ; Cl = 35.5 u)

Calculate the molecular mass of hydrogen bromide (HBr). (Atomic masses : H = 1 u ; Br = 80 u)

Calculate the molecular masses of the following compounds :

Hydrogen sulphide, H₂S

Calculate the molecular masses of the following compounds :

Carbon disulphide, CS₂

_{(Atomic masses : H = 1 u ; S = 32 u ; C = 12 u)}

Calculate the molecular masses of the following :

Oxygen, O₂

(Atomic masses : H = 1 u ; O = 16 u ; Cl = 35.5 u ; N = 14 u ; C = 12 u)

Calculate the molecular masses of the following :

Chlorine, Cl₂

(Atomic masses : H = 1 u ; O = 16 u ; Cl = 35.5 u ; N = 14 u ; C = 12 u)

Calculate the molecular masses of the following :

Ammonia, NH₃

(Atomic masses : H = 1 u ; O = 16 u ; Cl = 35.5 u ; N = 14 u ; C = 12 u)

Calculate the molecular masses of the following :

Carbon dioxide, CO₂

(Atomic masses : H = 1 u ; O = 16 u ; Cl = 35.5 u ; N = 14 u ; C = 12 u)

Calculate the molecular masses of the following compounds  :

Methane, CH₄

(Atomic masses : C = 12 u ; H = 1 u)

Calculate the molecular masses of the following compounds  :

Ethane, C₂H₆ 

(Atomic masses : C = 12 u ; H = 1 u)

Calculate the molecular masses of the following compounds  :

Ethene, C₂H₄ 

(Atomic masses : C = 12 u ; H = 1 u)