English Medium Class 9 - CBSE Question Bank Solutions

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)

Calculate the molecular masses of the following compounds  :

Ethyne, C₂H₂

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

Calculate the molecular masses of the following compounds :

Ethanol, C₂H₅OH

Which of the following elements has the same molecular mass as its atomic mass ?

Calculate the formula masses of the following compounds :

Sodium oxide, Na₂O

Calculate the formula masses of the following compounds :

Calcium carbonate

Calculate the formula masses of the following compounds :

1. Calcium chloride
2. Sodium carbonate

(Given : Atomic masses : Ca = 40 u ; Cl = 35.5 u ; Na = 23 u ; C = 12 u; O = 16 u)

How many molecules are present in one gram molecular mass of a substance ?

Convert 12 g of oxygen gas into moles.

Calculate the mass of 12.044 × 1025 molecules of oxygen (O2).

How many moles are there in 34.5 g of sodium ? (Atomic mass of Na = 23 u)