What is the density of a sample of ammonia gas (NH 3 ) if the pressure is 705 mm Hg and the temperature is 63.0°C?

Density of the gas = 0.57 g/L

Explanation:

We can solve this, by the Ideal Gases Law.

We know by Avogadro's Law that 1 mol of any gas will occupy the same volume if we measure the same temperature and pressure conditions.

1 mol of Ideal Gas occupies 22.4 L at STP (1 atm and 273K)

We can compare the two situations to determine the volume for the second one.

We convert the T° and the pressure

705 mmHg . 1 atm / 760 mmHg = 0.927 atm

63°C + 273 = 336 K

As n and R are the same, we have: P₁ . V₁ / T₁ = P₂ . V₂ / T₂

1 atm . 22.4L / 273K = 0927 atm . V₂ / 336K

(1 atm . 22.4L / 273K) . 336 K = 0.927 atm .V₂

27.5 atm . L  / 0.927 atm = V₂ → 29.7 L

1 mol of ammonia weighs 17 g

Density of the gas → mass / volume → 17 g / 29.7L = 0.57 g/L