Question

The molar mass of a certain gas is 49 g. What is the density of the gas in g/L at STP?

Answer 1

Answer:

$\boxed{\text{2.2 g/L}}$

Explanation:

We can use the Ideal Gas Law to calculate the density of the gas.

   pV = nRT

      n = m/M           Substitute for n

   pV = (m/M)RT     Multiply both sides by M

pVM = mRT            Divide both sides by V

  pM = (m/V) RT

     ρ = m/V             Substitute for m/V

 pM = ρRT              Divide each side by RT

$\rho = \frac{pM }{RT}$

Data:

p = 1.00 bar

M = 49 g/mol

R = 0.083 14 bar·L·K⁻¹mol⁻¹

T = 0 °C = 273.15 K

Calculation:

ρ = (1.00 × 49)/(0.083 14 × 273.15) = 2.2 g/L

The density of the gas is $\boxed{\text{2.2 g/L}}$.