Question

The molar heat of fusion for water is 6.01 kJ/mol. How much energy is released when 36.8 g of water freezes at its freezing point?

A. 6.12 kJ
B. 12.3 kJ
C. 108 kJ
D. 221 kJ

Answer 1

Your answer is 12.3 kJ. The molor heat of fusion kind of tells you A thing about it. I hope I could help! :)





Have a wonderful rest of the day.

Answer 2

Answer : The correct option is, (B) 12.3 KJ

Solution :

First we have to calculate the moles of water.

`\text{Moles of water}=\frac{\text{Mass of water}}{\text{Molar mass of water}}=(36.8g)/(18g/mole)=2.04mole`

Now we have to calculate the amount of heat released.

Formula used :

`q=n* \Delta H_(fusion)`

where,

q = heat released

n = number of moles = 2.04 mole

`\Delta H_(fusion)` = molar enthalpy of fusion of a substance = -6.01 KJ/mole

Now put all the give values in the above formula, we get the amount of heat released.

`q=(2.04mole)* (-6.01KJ/mole)=-12.3KJ`

The negative sign indicate heat released.

Therefore, the amount of heat released is, 12.3 KJ