ICSE CLASS 10 EMPIRICAL FORMULA AND PERCENTAGE COMPOSITION MCQs for Practice

ICSE CHEMISTRY MCQs on EMPIRICAL FORMULA  AND PERCENTAGE COMPOSITION

Choose the correct answer from A,B,C and D for each of the following statements.

Question 1

A Hydrocarbon is found to contain 75% of Carbon. Then the percentage of Hydrogen that compound has:

A) 75%

B) 25%

C) 30%

D) 50%

 

Question 2

The Relative Molecular Mass (RMM) of a compound is 180. What will be its Vapour Density?

A) 90

B) 180

C) 45

D) 10

 

Question 3

A gaseous compound has the formula X₂Y. The atomic weights are X-5 and Y-10. Find its Vapour Density (VD):

A) 5

B) 15

C) 20  

D) 10

 

Question 4

The Vapour Density of a substance is :

i) Half of RMM

ii) equal to RMM

iii) Twice the RMM

iv) 3 times the RMM

 

 

Question 5

The simplest whole number ratio of the number of atoms of each element present in a given compound.

A) Molecular formula

B) Unit formula

C) Empirical formula

D) Formula weight

 

Question 6

The molecular weight is equal to:

A) (Empirical Formula weight) / n

B) (Empirical formula weight) x n

C) Twice the Empirical formula weight

D) Half of empirical formula weight

 

Question 7

The Empirical formula of a compound is C₂H₅. Given n= 2, What is the Molecular formula of that compound?

A) C₂H₅

B) C₄H₈

C) C₂H₁₀
D) C₄H₁₀

 

Question 8

Which of the following compounds has the empirical formula CH₃?

A) CH₄

B) C₃H₆

C) C₂H₆

D) C₈H₁₂

 

Question 9

The Empirical formula of CH₃COOH:

A)    CHO

B)    COOH

C)    CO₂H

D)    CH₂O

 

Question 10

6.4g of Sulphur combines with Oxygen to form 12.8 g of its oxide. Find the percentage of Oxygen in it.

A) 15%

B) 25%
C) 50%

D) 75%

 

Question 11

19.2g of Carbon combines with 4.8g of Hydrogen completely to form a Hydrocarbon. Calculate percentage composition of that compound.

 

A) C-25% and H-75%

B) C-75% and H-25%

C) C-20% and H-80%

D) C-80% and H-20%

 

Question 12

The empirical formula formula of a compound is CH₂O and n=2. Find the molecular formula :

A) C₂H₄O₂

B) CHO

C) C₂H₂O₂

D) CH₂O₄

 

Question 13

The Molecular formula and Empirical formula of a compound are C₂H₄ and CH₂ respectively. What is the ratio between its Molecular weight and the Empirical Formula weight?

A) 1

B) 2

C) 3

D) 4

 

Question 14

Find the Relative Molecular Mass of Copper Sulphate crystals.

At. wt. H-1, O-16, S-32, Cu-64

A) 160

B) 200

C) 260

D) 250

 

Question 15

Find the percentage of Oxygen in Magnesium nitrate crystals [Mg(NO₃)₂.6H­₂O]

At.wt. H-1, N-14, O-16, Mg-24

A) 43.75%

B) 37.5%

C) 57%

D) 75%

 

Question 16

Calculate the RMM of Sulphuric acid and Sodium carbonate.

At. wt. H-1, C-12, O-16, Na-23, S-32

A) 98 and 100

B) 100 and 106

C) 98 and 106

D) 98 and 83

Question 17

A compound has the following percentage composition. Find its Empirical Formula and Molecular formula. Given n=2. N-87.5% and H – 12.5% (at. wt. H-1, N-14)

A) NH₂ and NH₄

B) NH and N₂H₄

C) N₂H and NH₄

D) NH₂ and N₂H₄