Question

A compound ($x$) with molar mass $108 \, \text{g mol}^{-1}$ undergoes acetylation to give a product with molar mass $192 \, \text{g mol}^{-1}$. The number of amino groups in the compound ($x$) is ______.

Answer 1

Correct Answer: 2

Each $\text{NH}_2$ group increases molecular weight by 42 upon acetylation:

$$192 - 108 = 84$$ $$\frac{84}{42} = 2$$

Thus, the compound $x$ has:

$$\text{2 amino groups.}$$