Question

In an experiment, the following four gases were produced. 11.2 L of which two gases at STP will weigh 14 g ?

• A. $N_{2}O$
• B. $N{O}_2$
• C. $N_2$
• D. $CO$

Answer 1

Answer: (C), (D)

The correct options are
C $N_2$
D $CO$

22.4 L of a gas at STP$=$ 1 mole.

11.2 L of a gas at STP$=$ 0.5 mole.

11.2 L of a gas at STP will weigh 14 g.

0.5 moles of a gas at STP will weigh 14 g.

1 mole of a gas at STP will weigh $\frac{1}{0.5}\times 14=28$ g.

The molecular weight of the gas is 28 g/mol.

Molecular weight of $N_{2}O=2\left(14\right)+16=44$ g/mol.

Molecular weight of $N{O}_2=14+2\left(16\right)=46$ g/mol.

Molecular weight of $N_2=2\left(14\right)=28$ g/mol.

Molecular weight of $CO=12+16=28$ g/mol.

Hence, 11.2 L of $N_2$ and $CO$ at STP will weigh 14 g.