When lead sulphide (2) is roasted in air, lead oxide (2) and sulfur dioxide are formed.

When lead sulphide (2) is roasted in air, lead oxide (2) and sulfur dioxide are formed. What volume of sulfur dioxide, measured at normal level, can be obtained from 23.9 g of lead sulfide (2)?

2PbS + 3O2 = 2PbO + 2SO2

Let’s find the amount of lead sulfide substance:

n (PbS) = m (PbS) / M (PbS) = 23.9 / 239 = 0.1 mol;

According to the stoichiometry of the reaction:

n (SO2) = n (PbS) = 0.1 mol;

Find the volume of sulfur dioxide:

V (SO2) = n (SO2) * VM = 0.1 * 22.4 = 2.24 liters.

Answer: V (SO2) = 2.24 liters.