Question

A 5.00 gram sample of magnesium sulfate hydrate (epsom salt) is heated in the lab to form anhydrous magnesium sulfate. After heating the substance, it is recorded that 2.86 grams of anhydrous magnesium sulfate remain. What is the chemical formula for this sample of magnesium sulfate hydrate

Answer 1

Answer:

The answer to your question is  MgSO₄ 5H₂O

Explanation:

Data

mass of MgSO₄ = 2.86 g

mass of H₂O = 2.14 g (5 - 2.86)

Process

1.- Calculate the molecular mass of the compounds

MgSO₄ = 24 + 32 + (16 x 4) = 120

H₂O = 16 + 2 = 18

2.- Convert the grams obtain to moles

                        120 g of MgSO₄  --------------- 1 mol

                         2.8 g                  ----------------  x

                         x = (2.8 x 1)/120

                        x = 0.024 moles

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

                         2.14 g           -------------------- x

                         x = (2.14 x 1)/18

                         x = 0.119

3.- Divide by the lowest number of moles

MgSO₄  = 0.024/0.024 = 1

H₂O = 0.119/ 0.024 = 5

4.- Write the molecular formula

                   MgSO₄5H₂O