Step-by-step explanation:
The molar volume corresponds to the volume occupied by any gas at STP, which is equal to 22.4 L.
So:
22.4 L ---- 1 mol
3.56 L ---- x mol
x = 0.159 moles
To find the molar mass we use the following formula:
molar mass = mass/moles
molar mass = 11.3/0.159
molar mass = 71.1
Answer: 71.1 g/mole