Question

A 1.50 liter flask at a temperature of 25°C contains a mixture of 0.158 moles of methane, 0.09 moles of ethane, and 0.044 moles of butane. What is the total pressure of the mixture inside the flask?

Answer 1

Applying the general gas equation : PV=nRT
V = 1.50 litres
R = 0.08205746 L atm/K mol
T = 25°C = 25+273 = 298 K
n = 0.158 moles+0.09 moles+ 0.044 moles = 0.292 moles
Re arranging the equation:
P = nRT / V = (0.158 + 0.09 + 0.044) mol x (0.08205746 L atm/K mol)
 x (25 + 273)K / (1.50 L)
= 4.76 atm
= 482 kPa
= 3617 mmHg