Question

The mass of 11.2 L of ammonia gas at STP is:

• A. 8.5 g
• B. 85 g
• C. 17 g
• D. 1.7 g
• E. 4.25 g

Answer 1

Answer: (A)

Molar mass of NH3 = 17 g $mo{l}^{-1}$
$\therefore$ 22.4 L of $N{H}_3$ at S.T.P. has mass = 17 g
11.2 L of $N{H}_3$ at S.T.P. has mas = $\frac{17}{2}$ = 8.5 g