A 6.0 L sample of nitrogen gas contains 0.50 mole of a gas. If enough gas is added to make a total of 0.75 moles at the same pressure and temperature, what is the resulting total volume of the gas?

2.3 L

4.8 L

7.5 L

9.0 L

9.0 L.

Explanation:

To solve this problem, we should use the general gas law of ideal gas:

PV = nRT.

where,

P is the pressure of the gas in (atm).

V is the volume of the gas in (L).

n is the no. of moles of the gas (mol).

R is the general constant for gases (R = 0.082 L. atm/mol. K).

T is the temperature of the gas in (K).

Since the P, T and R are constants, the variables are V and n.

∴ V₁n₂ = V₂n₁.

V₁ = 6.0 L & n₁ = 0.50 mol.

V₂ = ? L & n₂ = 0.75 mol.

∴ V₂ = (V₁n₂) / (n₁) = (6.0 L) (0.75 mol) / (0.50 mol) = 9.0 L.