Question

Substance X is a compound containing 632mg of manganese and 368mg of oxygen. Substance X is shown

below. Manganese has a relative atomic mass of 55 and oxygen has a relative atomic mass of 16. What is the
value of y in the formula below?

Answer 1

The empirical formula : MnO₂.

Further explanation

Given

632mg of manganese(Mn) = 0.632 g

368mg of oxygen(O) = 0.368 g

M Mn = 55

M O = 16

Required

The empirical formula

Solution

You didn't include the pictures, but the steps for finding the empirical formula are generally the same

• Find mol(mass : atomic mass)

Mn : 0.632 : 55 = 0.0115

O : 0.368 : 16 =0.023

• Divide by the smallest mol(Mn=0.0115)

Mn : O =

`\tt (0.0115)/(0.0115)/ (0.023)/(0.0115)=1/ 2`

The empirical formula : MnO₂