Question

A gas has density 2.41 g/liter at 25°C and 770 mm Hg. Calculate it's molecular mass (R = 0.0821 L atm.mol-1K-1.

ASAP!!!!!!!!! ​

Answer 1

Molecular mass, M = 58.20 g/mol.

Step-by-step explanation:

Given the following data;

• Density = 2.41 g/liter
• Temperature = 25°C
• Pressure = 770 mmHg
• Gas constant, R = 0.0821 L atm.mol-1K-1

Conversion:

760 mmHg = 1 atm

770 mmHg = 770/760 = 1.0131 atm

Temperature = 25°C = 273 + 25 = 298 K

To find the molecular mass, we would use the ideal gas law equation (density version);

PM = dRT

Where;

• P is the pressure.
• M is the molecular mass.
• d is the density of a substance.
• R is the ideal gas constant.
• T is the temperature.

Making M the subject of formula, we have;

`M = \frac {dRT}{P}`

Substituting into the formula, we have;

`M = \frac {2.41 * 0.0821 * 298}{1.0131}`

`M = \frac {58.9626}{1.0131}`

Molecular mass, M = 58.20 g/mol.