Questions: What is the molar mass of CH4? (C = 12.01 g / mol, H = 1.008 g / mol) A. 1 g / mol C. 13.02 g / mol B. 4 g / mol D. 16.04 g / mol

Solution Steps

The atomic masses given are:

• Carbon (C): \(12.01 \, \text{g/mol}\)
• Hydrogen (H): \(1.008 \, \text{g/mol}\)

Methane ($\mathrm{CH}_4$) consists of:

• 1 Carbon atom
• 4 Hydrogen atoms

The molar mass of $\mathrm{CH}_4$ is calculated by summing the masses of all the atoms in the molecule: \[ \text{Molar mass of } \mathrm{CH}_4 = (1 \times 12.01 \, \text{g/mol}) + (4 \times 1.008 \, \text{g/mol}) \] \[ = 12.01 \, \text{g/mol} + 4.032 \, \text{g/mol} \] \[ = 16.042 \, \text{g/mol} \]

Since the problem specifies significant digits, we round the result to four significant digits: \[ 16.042 \, \text{g/mol} \approx 16.04 \, \text{g/mol} \]

Final Answer