Question

a compound with mass 159 was found to contain 39.62% copper and 20.13% sulphur. suggest molecular formula for the compound

Answer 1

sorry friend its hard for me

Answer 2

Answer:

CuSO₄

Explanation:

The percentage composition of the elements are :

Copper = 39.62%

Sulphur = 20.13%

The remaining amount is Oxygen hence the percentage mass of Oxygen is :

Oxygen = 100% - (20.13% + 39.62%) =

= 40.25%

Molar mass of copper = 63

Molar mass of Oxygen = 16

Molar mass of Sulphur = 32

Relative atomic mass of the elements is given by :

Copper = 39.62 g

Sulphur = 20.13 g

Oxygen = 40.25 g

The respective moles are :

Copper = 39.62/63 = 0.6288

Sulphur = 20.13/32 = 0.62906

Oxygen = 40.25/16 = 2.5156

We divide by the smallest mole to get the mole ratio.

Copper = 0.6288/0.6288 = 1

Sulphur = 0.62906/0.6288 = 1.0004

Oxygen = 2.5156/0.6288 = 4.0006

The Empirical formula of the compound :

CuSO₄

From the Empirical formula we can get the molar mass.

63 × 1 + 32 × 1 + 16 × 4 = 159

Therefore this is the formula of the compound.