Question

A mixture of carbon and sulphur has a mass of 9.0 g. Complete combustion with excess oxygen gives 22.6 g of a mixture of carbon dioxide and sulphur dioxide. Find the mass of sulphur in the original mixture

Answer 1

Let x = mass C
and y = mass S
Two unknowns require two equations and solve them simultaneously.
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x + y = 9.0
x(molar mass CO2/atomic mass C) + y(molar mass SO2/atomic mass S) = 22.6
Solve for y.
Post your work if you get stuck.

Answer 2

3.00