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

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

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

Thus, the compound $x$ has:

$\text{2 amino groups.}$