Final answer:
The volume of the unknown gas at STP is 0.32 mol.
Step-by-step explanation:
The volume of a gas at standard temperature and pressure (STP) is given by the molar volume of the gas, which is approximately 22.4 L/mol.
Since the volume of the unknown gas is given as 14.3 mL, we need to convert it to liters by dividing by 1000: 14.3 mL ÷ 1000 = 0.0143 L.
Therefore, the volume of the gas at STP is 0.0143 L × (22.4 L/mol) = 0.32 mol.