What mass of ethane,C₂H₆,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl₃F?

Question

Quizplus · Accepted Answer

To solve this problem, we need to use the Avogadro's number which is 6.022*10^23 molecules/mol. First, we need to calculate the number of molecules in 3.00g of trichlorofluoromethane. The molar mass of CCl3F is  137.37 g/mol. So, the number of moles of CCl3F is 3.00g/137.37 g/mol = 0.02184 mol. The number of molecules in 0.02184 mol of CCl3F is 0.02184 mol * 6.022*10^23 molecules/mol = 1.316*10^22 molecules. Now, we need to find the mass of ethane which contains the same number of molecules as 1.316*10^22 molecules of CCl3F. The molar mass of ethane, C2H6, is 30.07 g/mol. The number of moles of ethane is (1.316*10^22 molecules) / (6.022*10^23 molecules/mol) = 0.02184 mol. The mass of ethane is 0.02184 mol * 30.07 g/mol = 0.655 g. Therefore, the answer is B.

What Mass of Ethane,C2H6,contains the Same Number of Molecules as 3.00

What Mass of Ethane,C₂H₆,contains the Same Number of Molecules as 3.00