Question

A compound contains $8\%$ sulphur by mass. The minimum molecular weight of the compound is:

• A. $100$
• B. $200$
• C. $350$
• D. $400$

Answer 1

Answer: (D)

$400$

The compound has sulphur$=8$%

$\therefore 8$ g of $S$ is present in $100$ g.

[Least molecular mass means that at least one atom of sulphur should be present in a molecule.]

$\therefore 32$ g of $S$ is present in $\frac{100}{8}\times 32=400$ g

Hence, option D is correct.