Final answer:
To find the amount of Cl in a 38.0 g sample of CF₂Cl₂, calculate the percentage by mass of Cl, which is 58.65%, and multiply by the sample mass to get approximately 22.29 grams of Cl.
Step-by-step explanation:
To calculate how many grams of Cl are in a 38.0 g sample of CF₂Cl₂, you need to know the percentage by mass of Cl in CF₂Cl₂. The molar mass of CF₂Cl₂ is 120.913 g/mol, and each molecule contains two Cl atoms. The atomic mass of Cl is approximately 35.45 g/mol, so the mass of Cl in CF₂Cl₂ is 2 × 35.45 g = 70.90 g. This mass corresponds to the Cl in 1 mole of CF₂Cl₂.
To find the percentage by mass of Cl in CF₂Cl₂, divide the mass of Cl in 1 mole (70.90 g) by the molar mass of CF₂Cl₂ (120.913 g/mol) and multiply by 100:
Percentage by mass of Cl = (70.90 g / 120.913 g/mol) × 100 = 58.65%
Now, use this percentage to find the mass of Cl in the 38.0 g sample:
Mass of Cl in sample = 38.0 g × (58.65 / 100) = 22.29 g
Therefore, there are approximately 22.29 grams of Cl in a 38.0 g sample of CF₂Cl₂.