Oxygen has a density of 1.43 g/l at stp. what is the density of oxygen at 1.30 atm?

At STP means Pressure = 1 atm and Temp = 273K

Density = mass/volume=grams/L

M = molar mass

P = pressure

R = gas constant

T = temp

Density = PM/RT

Density = (1.30 atm x 32 grams/mol) / (0.0821 x 273K) = 1.86 g/L