Extracting metals from their ores
2 marks · EasyA student heats 10.0 g of zinc sulfide (ZnS) strongly in air. The reaction converts all the ZnS into zinc oxide (ZnO) and releases sulfur dioxide gas.
If the mass of zinc oxide produced is 12.0 g, calculate the mass of sulfur dioxide given off.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
2.0 g (±0.1)
Common mistakes: Mixes up reactants and products
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Writes mass of ZnS + oxygen = mass of ZnO + SO2 or calculates by difference.
A1 · 1 mark · Correct calculation: 2.0 g SO2.
Worked solution
Total mass of reactants = mass of ZnS + mass of O2 (not given).
But mass lost equals mass of SO2 since rest is in ZnO.