The relative molecular mass of methane, CH₄, is 16.043. What is the relative molecular mass of ethane C₂H₆ and benzene C₆H₆?

To find the relative molecular mass of ethane (C₂H₆) and benzene (C₆H₆), we first need to know the atomic masses of the elements involved.

Calculating Ethane (C₂H₆)

Ethane consists of 2 carbon (C) atoms and 6 hydrogen (H) atoms. The atomic masses are approximately:

• Carbon (C): 12.01 g/mol
• Hydrogen (H): 1.008 g/mol

Now, we can calculate the relative molecular mass:

Relative Molecular Mass of C₂H₆:

2 × 12.01 + 6 × 1.008 = 24.02 + 6.048 = 30.07 g/mol

Calculating Benzene (C₆H₆)

Benzene contains 6 carbon atoms and 6 hydrogen atoms. Using the same atomic masses:

Relative Molecular Mass of C₆H₆:

6 × 12.01 + 6 × 1.008 = 72.06 + 6.048 = 78.11 g/mol

Summary of Results

• Ethane (C₂H₆): 30.07 g/mol
• Benzene (C₆H₆): 78.11 g/mol