Question

A compound contains 16% by mass of sulphur. What is the minimum molar mass of the compound?

• A. 400 g/mol
• B. 100 g/mol
• C. 200 g/mol
• D. 300 g/mol

Answer 1

The correct option is C 200 g/mol

At minimum the compound will contain 1 atom of S per molecule.
Let's consider that the compound contains 1 atom of S per molecule.
We know that, the molar mass of sulphur is 32 g

Given:
100 g of the compound contains 16 g of sulphur.
Mass of the compound that contains 1 mole of sulphur = molar mass of the compound = $\frac{100\times 32}{16}=200g/mol$