Question

A sample of copper (II) sulfate hydrate has a mass of 3.97 g. After heating, the CuSo that remains has a mass of 2.54 g. Determine the correct formula and name of the hydrate.

Answer 1

Answer:

The answer to your question is:     CuSO₄ 5H₂O

Name: copper (II) sulfate pentahydrate

Explanation:

Data

copper (II) silfate hydrate = 3.97 g

copper (ii) sulfate mass = 2.54g

Correct formula = ?

                                  CuSO₄ X H₂O

Process

Quantity of water = 3.97 - 2.54

                             = 1.43 g

MW of water

                            18 g of H2O ---------------- 1 mol

                            1.43 g           -----------------  x

                             x = (1.43 x 1) / 18

                             x = 0.079 moles of water

MW CuSO₄ = 160 g

                             160 g -----------------------  1 mol

                              2.54 g ---------------------   x

                              x = (2.54 x 1) / 160

                              x = 0.016 moles

Divide by the lowest number of moles

CuSO₂ = 0.016 / 0.016 = 1

H₂O = 0.079 / 0.016 = 4.9 ≈ 5

then, the formula will be

                                          CuSO₄ 5H₂O