Question

A 9.00L tank at 20.2°C is filled with 2.01g of dinitrogen difluoride gas and 13.6g of chlorine pentafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction of each gas. Round each of your answers to 3 significant digits.

gas	mole fraction
dinitrogen difluoride	__________
chlorine pentafluoride	__________

Answer 1

Molar mass of N2F2,

MM = 2*MM(N) + 2*MM(F)

= 2*14.01 + 2*19.0

= 66.02 g/mol

Molar mass of ClF5,

MM = 1*MM(Cl) + 5*MM(F)

= 1*35.45 + 5*19.0

= 130.45 g/mol

n(N2F2) = mass/molar mass

= 2.01/66.02

= 0.0304

n(ClF5) = mass/molar mass

= 13.6/130.45

= 0.1043

n(N2F2),n1 = 0.0304 mol

n(ClF5),n2 = 0.1043 mol

Total number of mol = n1+n2

= 0.0304 + 0.1043

= 0.1347 mol

Mole fraction of each components are

X(N2F2) = n1/total mol

= 0.0304/0.1347

= 0.226

X(ClF5) = n2/total mol

= 0.1043/0.1347

= 0.774

0.226

0.774