Here's how to calculate the molecular mass of butane (C₄H₁₀):

1. Find the atomic masses:

* Carbon (C): 12.011 g/mol

* Hydrogen (H): 1.008 g/mol

2. Multiply the atomic mass of each element by its subscript in the formula:

* Carbon: 12.011 g/mol * 4 = 48.044 g/mol

* Hydrogen: 1.008 g/mol * 10 = 10.08 g/mol

3. Add the results together:

* 48.044 g/mol + 10.08 g/mol = 58.124 g/mol

Therefore, the molecular mass of butane (C₄H₁₀) is 58.124 g/mol.