Question

when 5.0g of KOH is added to 100mL, of water, the temperature of the solution increases by 3 degrees celsius. Assume the density of the solution to be 1g/mL and specific heat capacity of the solution to be 4.184 J/g K.

a. calculate the amount of heat absorbed by the solution.

b. find the enthalpy change for the dissolution of KOH.

c. find the enthalpy change per mole KOH.

Answer 1

1.
q = mass H2O x specific heat H2O x (Tfinal-Tinitial)

2.
q/gram = q/5.0
q/mol = (q/5.0)*molar mass KOH
Divide by 1000 to express in kJ/mol which is the usual unit used.