In the laboratory a general chemistry student finds that when 2.84 g of kclo4(s) are dissolved in 107.70 g of water, the temperature of the solution drops from 22.82 to 20.34 °c. the heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.55 j/°c. based on the student's observation, calculate the enthalpy of dissolution of kclo4(s) in kj/mol. assume the specific heat of the solution is equal to the specific heat of water.

Answer : The enthalpy change of dissolution of is 54.3 kJ/mole

Explanation :

Heat released by the reaction = Heat absorbed by the calorimeter + Heat absorbed by the water

where,

q = heat released by the reaction

= heat absorbed by the calorimeter

= heat absorbed by the water

= specific heat of calorimeter =

= specific heat of water =

= mass of water = 107.70 g

= change in temperature =

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

Now we have to calculate the enthalpy change of dissolution of

where,

= enthalpy change = ?

q = heat released = 1.1123 kJ

m = mass of = 2.84 g

Molar mass of = 138.55 g/mol

Therefore, the enthalpy change of dissolution of is 54.3 kJ/mole

∠gdh and ∠edh on edg.

answer is c