What mass of water can be heated from 45C to 88C with 28 kj?
m=Q/(Cp*dT)
m is mass in kilograms(kg)
Q is the amount of heat (given as 28kJ)
Cp is the specific heat. (For water it is 4.19kJ/kg C).
dT is the difference between the temperatures (88-45)
m= 28/(4.19*(88-45))
If you solve this problem you get 0.15 kG.