Gas law Chemistry

Question

1) How many liters are occupied by 1.05 mol of nitrogen at 198◦C and 0.564 atm pressure?

2) A gas sample occupies 4.71 L at 39◦C. What is the pressure given that there are 1.18 mol of gas in the sample?

Answer 1

Use the ideal gas law: PV = nRT

P = pressure in atm = 0.564 atm

V = volume in liters = ?

n = moles = 1.05 mol

R = gas constant = 0.0821 Latm/Kmol

T = temperature in Kelvin = 198 + 273 = 471K

Solving for V:

V = nRT/P = (1.05)(0.0821)(471)/0.564

V = 71.99 L = 72.0 L (3 sig. figs)

PV = nRT and solving for P:

P = nRT/V = (1.18)(0.0821)(312)/4.71

P = 6.42 atm