Question

Calculate the theoretical percentage of water for the following hydrates.

(a) manganese(II) monohydrate, MnSO4 H2O
(b) manganese(II) tetrahydrate, MnSO4 4H2O

Answer 1

(a)
`\% H_2O=10.65\%`

(b)
`\% H_2O=32.2`

Step-by-step explanation:

Hello.

For this questions we must consider the ratio of the molar mass of water to hydrated compound molar mass as shown below:

(a) In this case, we can consider that inside the manganese (II) sulfate monohydrate, whose molar mass is 169.02 g/mol, there is one water molecule that has a molar mass of 18 g/mol, for which the theoretical percentage of water is:

`\% H_2O=(18g/mol)/(169.0g/mol) *100\%\\\\\% H_2O=10.65\%`

(b) In this case, we can consider that inside the manganese (II) sulfate tetrahydrate, whose molar mass is 223.1 g/mol, there are four water molecules that have a molar mass of 4*18 g/mol, for which the theoretical percentage of water is:

`\% H_2O=(4*18g/mol)/(223.1g/mol) *100\%\\\\\% H_2O=32.27\%`

Best regards.