calculate the density of O2 at STP ( 1 atm , 0 degrees celcius and at 25 degrees celsius and 760 mmhg

Answer 1

At STP:

1 mole O2 = 32 g

1 mole = 22.4 liters

density = mass/volume = 32g/22.4 liters = 1.43 g/liter

At 25ºC and 760 mm Hg:

PV = nRT and let n = 1 mole

(760 mm Hg)(V) = (1 mol)(62.36 mm Hg-L/Kmol)(298K)

V = 24.45 liters

1 mole = 32 g

density = mass/volume = 32g/24.45 liters = 1.31 g/liter

Answer 2

Hello Raven

Starting from the ideal gas law equation, PV = nRT, you can derive the following equation that allows to solve for the density of a gas very quickly.

d = MMP/ RT

where MM is the molar mass of the gas, P is the pressure, R is the gas constant, and T is the Kelvin temperature.

1) At STP

MM of O2 = 32 g/mol

P = 1 atm

R = 0.0821 L atm / mol K

T = 0 oC + 273 = 273 K

d = (32 x 1) / (0.0821 x 273) = 1.43 g/L

2) P = 760 mm Hg = 1 atm

R = 0.0821 L atm / mol K

T = 25 oC + 273 = 298 K

d = (32 x 1) / (0.0821 x 298) = 1.31 g/L