Chemistry

1What mass of CaO is formed from 50 g of CaCO₃ (Ca = 40, C = 12, O = 16)?

2A gas occupies 200 cm³ at 300 K. At constant pressure, its volume at 600 K is

3A gas has a density of 1.43 g/dm³ at s.t.p. Its molar mass is about

4The empirical formula of a compound with 40% C, 6.7% H and 53.3% O is

5In the equation N₂ + 3H₂ → 2NH₃, how many moles of hydrogen react with 2 moles of nitrogen?

6What volume of oxygen at s.t.p. is needed to burn 2 moles of hydrogen completely?

7How many moles are in 9 g of water (H2O = 18 g/mol)?

8A gas occupies 200 cm³ at 300 K. At constant pressure, its volume at 450 K is

9The relative molecular mass of H₂SO₄ (H = 1, S = 32, O = 16) is

10What is the molar mass of sulphuric acid, H₂SO₄? (H = 1, S = 32, O = 16)