Question

To make use of an ionic hydrate for storing solar energy, you place 422.0 kg of sodium sulfate decahydrate on your house roof. Assuming complete reaction and 100% efficiency of heat transfer, how much heat (in kJ) is released to your house at night

Answer 1

Complete Question

To make use of an ionic hydrate for storing solar energy, you place 422.0 kg of sodium sulfate decahydrate on your house roof. Assuming complete reaction and 100% efficiency of heat transfer, how much heat (in kJ) is released to your house at night? Note that sodium sulfate decahydrate will transfer 354 kJ/mol.

Answer:

The amount of energy released is
`x = 4.63650 *10^5 KJ`

Step-by-step explanation:

Number of moles is mathematically represented as

`n =(mass)/(Molar\ Mass)`

substituting
`422.0kg = 422 *10^3g` for mass of sodium sulfate decahydrate(
`Na_2 SO_4 \cdot 10H_2 O`),
`322.2g/mol` (This value is a constant )for the molar mass of sodium sulfate decahydrate

`n= (422*10^3)/(322.2)`

`= 1309.7 \ moles`

From the question we are told that

1 mole of sodium sulfate decahydrate generates
`354KJ` of energy

So 1309.7 mole would generate x

Now stating the relation mathematically

1 mol → 354KJ

1309.7 mol → x

=>
`x = 4.63650 *10^5 KJ`