A2.35 g sample of an unknown gas at 55 ∘c and 1.05 atm is stored in a 1.85 l flask.

what is the density of the gas and molar mass

Molar mass =  32.64 g / mol.

The density of gas is 1.3 × 10⁻³g/mL.

Explanation:

Given data:

Mass of sample = 2.35 g

Pressure = 1.05 atm

Volume = 1.85 L    (1.85 × 1000 = 1850 ml)

Temperature = 55 °C    (55+ 273.15 = 328.15 K)

Density = ?

Formula:

d = m/ v

The volume of flask would be the volume of gas.

d = 2.35 g / 1850 mL = 0.0013 g/mL or 1.3 × 10⁻³g/mL

The density of gas is 1.3 × 10⁻³g/mL.

Molar mass:

Now we will calculate the moles of a gas first in order to find the molar mass of a gas.

Formula:

PV =nRT

n = number of moles.

n = PV / RT

n = 1.05 atm × 1.85 L / 0.0821 atm. dm³. K⁻¹ . mol⁻¹ × 328.15 K

n = 1.9425 atm . L / 26.941115 atm . dm.³mol⁻¹

n = 0.072 mol

Now we will find the molar mass.

Number of moles = mass / molar mass

0.072 mol = 2.35 g / molar mass

Molar mass = 2.35 g / 0.072 mol

Molar mass =  32.64 g / mol

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