1. Determine the mass of 100 mL of solution for each reaction (assume the density of each solution is 1.00 g/mL).
2. Determine the temperature change, Δt, for each reaction.
3. Calculate the heat released by each reaction, q, by using the formula:
q = Cp•m•Δt(Cp = 4.18 J/g°C)
Convert joules to kJ in your final answer.
4. Find ΔH ( ΔH = -q ).
5. Calculate moles of NaOH used in each reaction. In Reactions 1 and 2, this can be found from the mass of the NaOH. In Reaction 3, it can be found using the molarity, M, of the NaOH and its volume, in L.
6. Use the results of the Step 4 and Step 5 calculations to determine ΔH/mol NaOH in each of the three reactions.
7. To verify the results of the experiment, combine the heat of reaction (ΔH/mol) for Reaction 1 and Reaction 3. This sum should be similar to the heat of reaction (ΔH/mol) for Reaction 2. Using the value in Reaction 2 as the accepted value and the sum of Reactions 1 and 3 as the experimental value, find the percent error for the experiment.