Answer is: 0.069 moles of of gas are present.
V(gas) = 1.07 L; volume.
T = 22.0°C = 295.15 K; temperature of gas.
p = 1.56 atm; pressure of gas.
R = 0.08206 L·atm/mol·K; gas constant.
Ideal gas law: p·V = n·R·T.
n = p·V / R·T.
n(gas) = 1.56 atm · 1.07 L / 0.08206 L·atm/mol·K · 295.15 K.
n(gas) = 0.069 mol; amount of substance.