Final answer:
The mass of ethane in the sample is 7.946 grams, calculated by multiplying the given moles (0.2643) by the molar mass of ethane (30.067 g/mol).
Step-by-step explanation:
To calculate the grams of ethane present in a sample containing 0.2643 moles when the molar mass of ethane is 30.067 g/mol, the following equation should be used:
Mass (g) = moles × molar mass (g/mol)
Substitute the given values into the equation:
Mass (g) = 0.2643 moles × 30.067 g/mol
Mass (g) = 7.946 g (grams of ethane)
This result represents the mass of ethane in the sample based on the moles provided and the molar mass of ethane.