When a 5.00 g 5.00 g sample of KBr KBr is dissolved in water in a calorimeter that has a total heat capacity of 2.26 kJ ⋅ K − 1 , 2.26 kJ⋅K−1, the temperature decreases by 0.370 K . 0.370 K. Calculate the molar heat of solution of KBr .

Answer : The molar heat of solution of KBr is, 19.9 kJ/mol

Explanation :

First we have to calculate the heat absorbed by calorimeter.

where,

q = heat absorbed = ?

c = specific heat capacity of calorimeter =

= change in temperature = 0.370 K

Now put all the given values in the above formula, we get:

Now we have to calculate the molar heat of solution of KBr.

where,

= enthalpy change = ?

q = heat released = 0.8362kJ

m = mass of = 5.00 g

Molar mass of = 119 g/mol

Now put all the given values in the above formula, we get:

Thus, the molar heat of solution of KBr is, 19.9 kJ/mol