What volume of sulfur oxide iv is formed by the interaction of sulfuric acid with 200 g of silver, containing 10 ℅ impurities.

2Ag + 2H2SO4 = Ag2SO4 + SO2 + 2H2O

Solution formulas:
α = (m in-va) / (m solution); n = m / M; n = V / Vm

Decision:
α (Ag) pure = 100% – α impurities = 100% – 10% = 90% = 0.9
0.1 = (m impurities) / (m solution)
m impurities = 0.1 * 200 = 20 g
if the mixture is 200g, and the impurities are 20g, then the mass of the pure:
m (Ag) = 200-20 = 180 g.
n (Ag) = (180 g) / (108 g / mol) = 1.7 mol
n (Ag) is 2 times more than n (SO2)
n (SO2) = 1.7 / 2 = 0.83 mol
V (SO2) = n * Vm = 0.83 mol * 22.4 l / mol = 18.7 l
Answer: V (SO2) = 18.7 l