In an experiment a student mixes a 50. 0 ml sample of 0. 100 m agno3(aq) with a 50. 0 ml sample of 0. 100 m nacl(aq) at 20. 0°c in a coffee-cup calorimeter. Which of the following is the enthalpy change of the precipitation reaction represented above if the final temperature of the mixture is 21. 0°c? (assume that the total mass of the mixture is 100. G and that the specific heat capacity of the mixture is 4. 2 j/(g °c). ).