Question

5. What is the molar mass of ethanol (C2H5OH)?

A) 45.06 g/mol
C) 30.03 g/mol
B) 34.06 g/mol
D) 46.07 g/mol

Answer 1

D) 46.07 g/mol

The molar mass is given by the sum of the atomic masses of the component elements of the substance.

In our case, the substance is ethanol or C₂H₅OH.

`A_C=12.011`

`A_H=1.0079`

`A_O=15.9994`

`\mathcal M_(C_2H_5OH) = 2 * A_C + 6 * A_H + A_O = 2 * 12.011 + 6 * 1.00079+ 15.999 4= 24.022 + 6.0474 + 15.9994= 46.069≈ \boxed{46.07 (g)/(mol)}`