Question

The molecular mass of butane is

• A. 58 u
• B. 35 u
• C. 56 u
• D. 52 u

Answer 1

The correct option is A

58 u

The mass of one molecule of an element or a compound is termed as molecular mass. It can be calculated by finding the sum of the atomic masses of the total number of different types of atoms present in one molecule of the substance.

The molecular formula of butane is $C_4{H}_{10}$
The atomic mass of carbon is 12 u.
The atomic mass of hydrogen is 1 u.

The molecular mass of $C_4{H}_{10}$ = $4\times \text{Atomic mass of carbon}+10\times \text{Atomic mass of hydrogen}$
The molecular mass of $C_4{H}_{10}$= $4\times 12+10\times 1$ = 58 u.