Final answer:
The volume of gas at STP can be calculated using the molar volume of an ideal gas. To find the volume of 67.8 g of Cl2 gas at STP, first convert the mass into moles by dividing it by the molar mass of Cl2. Then, use the molar volume to calculate the volume.
Step-by-step explanation:
The volume of gas at STP, or Standard Temperature and Pressure, can be calculated using the molar volume of an ideal gas, which is 22.41 L/mol. To calculate the volume of 67.8 g of Cl2 gas at STP, we need to first convert the mass into moles by dividing it by the molar mass of Cl2, which is 70.906 g/mol. Once we have the number of moles, we can use the molar volume to calculate the volume.
First, let's calculate the number of moles:
67.8 g Cl2 x (1 mol Cl2 / 70.906 g Cl2) = 0.956 mol Cl2
Now, we can use the molar volume to find the volume:
0.956 mol Cl2 x (22.41 L/mol) = 21.43 L