An apparatus consists of a 4.0 dm^3 flask containing nitrogen gas at 25°c and 803 kPa, it is joined by a valve to a 10.0dm^3 flask containing argon gas 25°c and 47.2KPa. The valve is opened and the gases mix, what is the partial pressure of each gas and calculate the total pressure of the gas mixture

so total pressure is = 261.92 kPa

partial pressure of Ar gas = 33.50 Kpa

partial pressure of N2 gas = 227 kPa

Explanation:

PV = nRT

n = PV / RT

as we know that 1dm3 = 1 Liter

smaller flask before mixing

ideal gas constant

n = (803 kPa) x (4L) / ((8.3144621 L kPa/K mol) x (25 + 273 K))

n = (3212 kPa L) / ((8.3144621 L kPa/K mol) x (298 K))

n = (3212 kPa L) / 2477.7

n = 1.29 mol

In the larger flask:

n = (47.2 kPa) x (10 L) / ((8.3144621 L kPa/K mol) x (25 + 273 K)) =

n = (472 kpaL / 2477.7

n = 0.19 mol

PV = nRT

P = nRT / V

After mixing:

P = (1.29 mol + 0.19 mol) x (8.3144621 L kPa/K mol) x (25 + 273 K) / (4 L + 10 L)

= (1.48) x (2477.7 / (14 L)

= 261.92 kPa total pressure

so total pressure is = 261.92 kPa

a)

(261 kPa) x (0.19 mol Ar) / (1.29 + 0.19mol) =

= 49.59/1.48 = 33.50 Kpa for Arg

b)

(261 kPa total) - (33.50 kPa Ar) = 227 kPa for N2

partial pressure of Ar gas = 33.50 Kpa

partial pressure of N2 gas = 227 kPa