Mixed delta H problems, chemistry i need help!!?

Question

1. When 1.00g of sodium hydroxide dissolved in 50g of water in a calorimeter the temperature of the water rises from 20 degrees Celsius to 25.5. Calculate the heat of solution for sodium hydroxide.

2. Determine the expected final temprature for the solution formed when 25mL of 2.00 mol/litre NaOH is added to 50mL of 1.00 mol/litre HCl. The initial temperature of both solutions was 20 degrees celsius and the molar heat of neutralisation is 57.0 KJ

3. When 100mL of 0.5mol/litre KOH is added to 100mL of 0.5 mol/litre HNO3 in a calorimeter, the temperature rises from 19 to 27.3 Calculate the heat of neutralisation for the reaction.

4. To measure the heat of combustion of ethanol some was placed in a weighed spirit burner and used to heat a copper beaker containing 500g water. after the temperature of the water and its container had risen from 13.2 to 24.6, the burner was extinguished and re-weighed. 0.81g ethanol had reacted. The mass of the copper beaker was 47.2g. Using 0.39 and 4.19 j/k/g for the specific heat capacities of copper and water respectively, calculate the heat of combustion of ethanol.

Answer 1

1)  What changed?  50g of water went from 20.0°C to 25.5°C.

Heat source?  Dissolving NaOH into the water.

∆H = mc∆T = (.050 kg)(4184 J kg^-1 K^-1)(5.5 K)

I trust you have a caluculator.

Work on the rest similarly.