Question

A power company burns approximately 500 tons of coal per day to produce electricity. If the sulphur content of the coal is 1.20 % by weight, how many tons $SO_2$ are dumped into the atmosphere per hour?

Answer 1

0.5 tons $SO_2$

Answer 2

1. Calculate the total mass of sulfur burned per day: The power company burns 500 tons of coal per day, and the coal contains 1.20% sulfur by weight. Mass of sulfur per day = (1.20 / 100) × 500 tons = 0.012 × 500 tons = 6 tons.

2. Determine the mass of $SO_2$ produced from the sulfur: Sulfur burns in the presence of oxygen to produce sulfur dioxide according to the balanced chemical equation: $S + O_2 \rightarrow SO_2$ From the molar masses: Molar mass of S = 32 g/mol Molar mass of $SO_2$ = 32 (for S) + 2 × 16 (for O) = 64 g/mol According to the stoichiometry, 32 tons of sulfur produces 64 tons of sulfur dioxide. Therefore, 1 ton of sulfur produces (64/32) = 2 tons of sulfur dioxide. Mass of $SO_2$ produced per day = Mass of sulfur per day × 2 Mass of $SO_2$ per day = 6 tons × 2 = 12 tons.

3. Calculate the mass of $SO_2$ dumped into the atmosphere per hour: Since there are 24 hours in a day: Mass of $SO_2$ per hour = Mass of $SO_2$ per day / 24 hours Mass of $SO_2$ per hour = 12 tons / 24 hours = 0.5 tons/hour.