Question

I WILL MARK YOU BRAINLIEST!!!!! A compound containing only carbon and hydrogen is found to contain 42.88% carbon. It has a molecular weight of 56.02. What is its molecular
formula?
Please show me how you solved it, it would really be appreciated

Answer 1

Answer:

C₂H₃₂

Explanation:

Given parameters:

Mass percentage of carbon  = 42.88%

Mass percentage of hydrogen  = 100 - 42.88  = 57.12%

Molecular weight  = 56.02

Unknown:

Molecular formula  = ?

Solution:

To solve this problem, we need to find the empirical formula of the compound first. The empirical formula is the simplest formula of a substance.

 Therefore;

Elements                     Carbon                             Hydrogen

Percentage

composition                  42.88                                   57.12

Molar mass                       12                                         1

Number of moles         42.88/12                               57.12/1

                                         3.57                                     57.12

Simplest

ratio                               3.57/3.57                               57.12/3.57

                                             1                                            16

Empirical formula of the compound is CH₁₆

     Molar mass of  CH₁₆  = 12 + 16(1) = 28g/mol

Multiplying index  = $\frac{molecular weight}{28}$   = $\frac{56.02}{28}$    = 2

Molecular formula  = (CH₁₆)₂   = C₂H₃₂