10th class Chemistry, Chapter 15: Stoichiometry MCQs

1. Volume occupied by 15 moles of ammonia gas at RTP:

1. (A) 224 dm³
2. (B) 160 dm³
3. (C) 360 dm³ ✓
4. (D) 265 dm³

2. How many moles of natural gas CH₄ will be present in a cylinder if its volume is 18 dm³ at RTP?

1. (A) 0.75 mol ✓
2. (B) 0.67 mol
3. (C) 0.85 mol
4. (D) 0.56 mol

3. What will the molar concentration of potassium hydroxide solution if 2.0 g of it are dissolved in 100 cm³ of solution?

1. (A) 0.36 mol/dm³ ✓
2. (B) 0.53 mol/dm³
3. (C) 0.70 mol/dm³
4. (D) 0.45 mol/dm³

4. What will be the mass of NaCl needed to make up 15 dm³ of its solution with a concentration of 0.7 g/dm³?

1. (A) 21 g
2. (B) 10.5 g ✓
3. (C) 31.5 g
4. (D) 5.4 g

5. Find out the concentration of H₂SO₄ in mol/dm³ if its 10 cm³ react with 20 cm³ of NaOH solution having concentration 0.1 mol/dm³.

1. (A) 0.01 mol/dm³
2. (B) 0.001 mol/dm³
3. (C) 0.1 mol/dm³ ✓
4. (D) 0.15 mol/dm³

6. If the molar mass of a compound is 178 g/mol and its empirical formula is C₃H₅O₃. What is its molecular formula?

1. (A) C₃H₅O₃
2. (B) C₆H₁₀O₆ ✓
3. (C) C₉H₁₅O₉
4. (D) C₈H₁₀O₈

7. When natural gas burns in air, which component is the limiting reactant?

1. (A) Both components
2. (B) Neither component is a limiting reactant
3. (C) Air
4. (D) Natural gas ✓

8. If the actual yield of a compound is 0.198 g while the theoretical yield is 0.217 g. What will be the percentage yield?

1. (A) 50%
2. (B) 91.2% ✓
3. (C) 80%
4. (D) 90%

9. The standard conditions used for measuring gas volumes at room temperature (RTP) are:

1. (A) 0 °C and 1 atm
2. (B) 25 °C and 1 atm ✓
3. (C) 25 °C and 2 atm
4. (D) 100 °C and 1 atm

10. One mole of any gas occupies a volume of ____ at RTP.

1. (A) 22.4 dm³
2. (B) 12 dm³
3. (C) 24 dm³ ✓
4. (D) 48 dm³

11. One mole of each gas has the same number of molecules, the same volume but a different:

1. (A) colour
2. (B) pressure
3. (C) mass ✓
4. (D) temperature

12. Number of moles of a gas =

1. (A) volume at RTP x molar volume
2. (B) mass x volume
3. (C) volume at RTP / molar volume ✓
4. (D) molar volume / volume at RTP

13. The number of moles of nitrogen gas in 2.5 dm³ at RTP is:

1. (A) 0.10 ✓
2. (B) 0.25
3. (C) 1.0
4. (D) 2.5

14. The volume of 0.5 mole of hydrogen at RTP is:

1. (A) 24 dm³
2. (B) 6 dm³
3. (C) 12 dm³ ✓
4. (D) 48 dm³

15. The volume occupied by 200 g of carbon dioxide at RTP is about:

1. (A) 109 dm³ ✓
2. (B) 24 dm³
3. (C) 44 dm³
4. (D) 200 dm³

16. The unit of molar concentration is:

1. (A) g/dm³
2. (B) mol/g
3. (C) mol/dm³ ✓
4. (D) g/mol

17. The unit used for mass/volume concentration is:

1. (A) dm³/g
2. (B) g/mol
3. (C) mol/dm³
4. (D) g/dm³ ✓

18. The concentration of a solution containing 20 g of NaCl in 0.2 dm³ is:

1. (A) 100 g/dm³ ✓
2. (B) 10 g/dm³
3. (C) 4 g/dm³
4. (D) 40 g/dm³

19. 500 cm³ of HCl contains 1.8 g of HCl. Its concentration in g/dm³ is:

1. (A) 0.9
2. (B) 1.8
3. (C) 3.6 ✓
4. (D) 7.2

20. The mass of copper sulphate dissolved in 2 dm³ of solution having concentration 15 g/dm³ is:

1. (A) 7.5 g
2. (B) 15 g
3. (C) 30 g ✓
4. (D) 60 g