Question

Calculate the pressure in atmospheres of 0.5 mol of Helium ( He) at 20°C & occupying 2.50 L.

Answer 1

Answer:

4.811 atm.

Explanation:

• We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = ?? atm).

V is the volume of the gas in L (V = 2.5 L).

n is the no. of moles of the gas in mol (n = 0.5 mol).

R  is the general gas constant (R = 0.0821 L.atm/mol.K),

T is the temperature of the gas in K (T = 20°C + 273 = 293 K).

∴ P = nRT/V = (0.5 mol)(0.0821 L.atm/mol.K)(293 K)/(2.5 L) = 4.811 atm.