1) A student placed 50.0mL of 2.05mol/L NaOH in a coffee-cup calorimeter at 20.4°C. After quickly stirring the mixture, its temperature rose to 28.2°C. Determine the enthalpy change for the reaction:
2NaOH(aq) + H2SO4(aq) --> 2H2O(l) + Na2SO4(aq)
I tried converting NaOH and H2SO4 into moles, and then finding the q=mcΔT of it, but you don't have the c of the compounds so I couldn't do that.
I also have another question:
2) Determine the energy released in the reaction of 1.00g of sodium with water.
2Na(s) + 2H2O(l) --> H2(g) + 2NaOH (aq) ΔH = -368.4kJ
So for this, I converted the sodium into moles. Then I plugged the moles and the combustion enthalpy into the equation ΔH=nΔHx to get 16.02kJ/mol. However, the answer says that it's 8.01kJ. What did I do wrong?