Master Class 9 Science – Atoms and Molecules with Our MCQ Mock Test!

Are you confident about the laws of chemical combination, atomic structure, and writing chemical formulas? Test your understanding with this MCQ-based mock test on Atoms and Molecules, designed specially for Class 9 students. This test covers all key concepts — from Dalton’s atomic theory and the law of conservation of mass to mole concept, atomic mass, molecular mass, and numerical problems based on these topics.

With well-curated multiple-choice questions following the latest CBSE syllabus, this mock test gives you a complete exam-like experience. It helps you strengthen your concepts, improve accuracy, and identify weak areas for focused revision. Perfect for both school exams and quick self-assessment!

Attempt now and see how strong your basics are in Atoms and Molecules!

1. Which is not represented by 1 mole of nitrogen gas ?

 
 
 
 

2. How many moles of electrons weigh equal to one kilogram? [Mass of 1 e = 9.1 × 10–31 kg]

 
 
 
 

3. Which pair of species contains same percentage of carbon?

 
 
 
 

4. The mass of sodium in 5.85 g of NaCl is

 
 
 
 

5. How many atoms are present in 52 u of He ?

 
 
 
 

6. Molecular weight of CuSO4. 5H2O is equal to [Cu = 63.5 u, S = 32 u, O = 16 u, H = 1 u]

 
 
 
 

7. Which of the following is correct statement ?

 
 
 
 

8. A sample of AlF3 contains 3.0 × 1024 F– ions. The number of formula units of this sample is

 
 
 
 

9. Which of the following contains maximum number of atoms ?

 
 
 
 

10. The formula of Ammonium phosphate is

 
 
 
 

11. The balancing of chemical equation is based on

 
 
 
 

12. 2 moles of H atoms at STP occupy volume of

 
 
 
 

13. NaOH (aq) + HNO3 (aq) → NaNO3 (aq) + H2O (l) In this reaction Nitric acid acts as

 
 
 
 

14. If isotopic distribution of C-12 and C-14 are 98% and 2% respectively, then number of C-14 atoms in 12 g of carbon is

 
 
 
 

15. The mass of magnesium oxide formed by burning 1.2 g of Mg in excess of oxygen is

 
 
 
 

16. Out of 1.0 g oxygen gas, 1.0 g of oxygen atoms and 1.0 g of ozone, the maximum number of atoms are contained in

 
 
 
 

17. The mass of 18 ml of water (H2O) at 4° C is equal to

 
 
 
 

18. Which of the following statements is not true about an atom?

 
 
 
 

19. Identify the correct symbol of Gold.

 
 
 
 

20. Arrange the following in increasing order of number of molecules.

I. 0.5 mol of H2
II. 4.0 g of H2
III. 18 g of H2O
IV. 2.2 g of CO2

 
 
 
 

21. Arrange the following in decreasing order of mass

I. 1023 molecules of H2

II. 0.1 mol of H2O

III. 0.01 mole of atoms of Nitrogen

IV. 2.24 L of O2 at STP

 
 
 
 

22. 1.5 g of hydrocarbon on combustion in excess of oxygen produces 4.4 g of CO2 and 2.7 g of H2O, the data illustrates

 
 
 
 

23. 18 g of water is electrolysed. The weight of oxygen formed will be

 
 
 
 

24. If the density of water is 1 g cm–3, then the volume occupied by one molecule of water is approximately

 
 
 
 

25. The combining capacity of an element is called

 
 
 
 

26. Identify the correct one from the following statements.

 
 
 
 

27. Which of the following correctly represents 360 g of water?

(i) 2 moles of H2O

(ii) 20 moles of water

(iii) 6.022 × 1023 molecules of water

(iv) 1.2044 × 1025 molecules of water

 
 
 
 

28. An element has 8% of sulphur. What will be the minimum molecular weight of the compound ?

 
 
 
 

29. The number of atoms present in 0.5 mol of nitrogen atoms is same as in

 
 
 
 

30. Which of the following illustrates the law of conservation of mass ?

 
 
 
 

Question 1 of 30