Comment
Share
Q)

# Substance is found to contain $7 \%$ nitrogen, The minimum molecular weight of it is

$(a)\;70 \\ (b)\;200 \\(c)\;100 \\(d)\;700$

$100\;g$ of substance has $7\;g$ of nitrogen.
$\therefore \; xg$ of substance has $\large\frac{7}{100} \times $$xg of nitrogen For minimum molecular weight, it must have at least one N atom. \therefore \large\frac{7}{100}$$\times x =14$
$x= \large\frac {14 \times 100}{7}$$=200$