Chemistry

Question 1

1What is the mass of 0.25 mol of sodium hydroxide, NaOH? (Na = 23, O = 16, H = 1)

Easy

A. 40 g B. 4 g C. 10 g D. 160 g

Question 2

2How many molecules are in 3.6 g of water? (H₂O = 18; L = 6.02 × 10²³)

Hard

A. 1.20 × 10²³ B. 6.02 × 10²³ C. 3.6 × 10²³ D. 2.17 × 10²⁴

Question 3

3The volume occupied by 1 mole of a gas at s.t.p. is

Easy

A. 1 dm³ B. 6.02 dm³ C. 24 dm³ D. 22.4 dm³

Question 4

4How many moles are in 11.2 dm³ of a gas at s.t.p.?

Easy

A. 1 mol B. 11.2 mol C. 0.5 mol D. 2 mol

Question 5

5The mass of 2 moles of oxygen molecules (O = 16) is

Easy

A. 16 g B. 64 g C. 128 g D. 32 g

Question 6

6The mass of 3.01 × 10²³ molecules of NH₃ (N = 14, H = 1) is

Hard

A. 4.25 g B. 8.5 g C. 17 g D. 34 g

Question 7

7The number of atoms in 0.5 mol of carbon is

Easy

A. 1.2 × 10²⁴ B. 6.02 × 10²³ C. 12 D. 3.01 × 10²³

Question 8

8What volume does 1 mol of any gas occupy at s.t.p.?

Easy

A. 22.4 dm³ B. 1 dm³ C. 6.02 dm³ D. 24.0 cm³

Question 9

9What volume at s.t.p. is occupied by 8.8 g of CO₂? (C = 12, O = 16)

Hard

A. 8.8 dm³ B. 22.4 dm³ C. 2.24 dm³ D. 4.48 dm³

Question 10

10How many moles are in 20 g of NaOH (Na = 23, O = 16, H = 1)?

Easy

A. 20 mol B. 0.5 mol C. 2 mol D. 0.25 mol