Question

A sample of gas has a mass of 0.673g. Its volume is 250.0mL at a temperature of 83 degrees C and a pressure of 747 torr. The sample is composed of which of the following gases?
(A) Xe
(B)Ar
(C)SO3
(D)CO2
(E)H2

Answer 1

Answer:

Explanation:

Given data:

Mass of sample = 0.673 g

Volume = 250.0 mL (0.25 L)

Temperature = 83°C (273+83= 356 k)

Pressure = 747 torr (747/760 = 0.98 atm)

Gas type = ?

Solution:

PV = nRT

n = PV/RT

n = 0.98 atm× 0.25 L / 0.0821 atm. L/mol.K × 356 k

n = 0.245 / 29.23/mol

n = 0.01 mol

Number of moles = mass/ molar mass

Molar mass = 0.673 g /  0.01 mol

Molar mass = 67.3 g/mol

molar mass of  CO2 = 44 g/mol

molar mass of  H2 = 2.016 g/mol

molar mass of  SO3 = 80.066 g/mol

molar mass of  Ar = 40 g/mol

molar mass of  Xe = 131.3 g/mol

So non of these gases are present.