Question

The density (g/L) of CO2 gas at STP ( 273 K, 1.00 atm) is

Answer 1

The density : 1.96 g/L

Further explanation

Ideal gas Law

Pv=nRT

where  

P = pressure, atm , N/m²  

V = volume, liter  

n = number of moles  

R = gas constant = 0.082 l.atm / mol K (P= atm, v= liter),or 8,314 J/mol K (P=Pa or N/m², v= m³)  

T = temperature, Kelvin  

so for density,

MW CO₂ = 44 g/mol

$\tt \rho=\dfrac{P\times MW}{RT}\\\\\rho=\dfrac{1\times 44}{0.082\times 273}\\\\\rho=1.96~g/L$