heat of combustion (1 Viewer)

[zxreth]

1.In a polystyrene calorimeter, 1g of sodium hydroxide crystals was dissolved in 50g of water. The initial temperature of the water was 21.5°C. The maximum temperature of the mixture was 26.2°C. Assuming the specific heat capacity of the mixture was 4.2J/K/g. calculate the:
a) enthalpy change for the reaction
b)molar heat of solution for sodium hydroxide

2.In a polystyrene calorimeter, 11g of solid calcium chloride hexahydrate was dissolved in 100g of water to produce 111g of solution. The initial temperature was 25°C. Given
CaCl2 . 6H2O(s) à Ca2+(aq)+2Cl-(aq)+6H2O(l) H=+18kJ
Calculate the final temperature of the solution. Assume no heat lost and that the specific heat capacity of the solution is 4.1J/K/g

3.A 200g sample of ice at -20°C is warmed slowly to 0°C without melting. Calculate the heat energy required for this process. (NOTE: ice = 2.1 J/K/g)

any help would be great
thanks!