Question

Using 0.082 as your R value, how many mols of a gas are present in a 10L container, at 250K under 0.1 atm of pressure?

Answer 1

First, we assume ideal gas conditions, so we apply the ideal gas law:

p x V = n x R x T (1)

p = pressure, in atm = 0.1 atm

V = volume, in L = 10 L

n = number of moles = unknown

T = temperatur, in K = 250 K

R = gas constant, in this case in (atm L/mol K) = 0.082

From (1), we clear n:

n = p x V/ R x T = (0.1 atm x 10 L)/ (0.082 atm L/mol K x 250 K) = 0.049 moles approximately

Answer: n = 0.049 moles