Question

The empirical formula for a compound is c2h5 and its formula mass is 58 amu. what is its molecular formula?

Answer 1

Molecular formula of compound is C4H10

Answer 2

Answer: $C_4H_{10}$

Explanation:

Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.  

Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.  

To calculate the molecular formula, we need to find the valency which is multiplied by each element to get the molecular formula.

Given empirical formula is $C_2H_5$ Empirical mass =$2\times 12+1\times 5=29amu$

The equation used to calculate the valency is:

$n=\frac{\text{molecular mass}}{\text{empirical mass}}=\frac{58}{29}=2$

The molecular formula will be $C_2H_5\times 2=C_4H_{10}$