2- enthalpy change

Question 1

how to measure △H1 and △H2

Answer 1

-CuSo4 and CuSo4.5H2O are separately dissolved in water
-temp change of the reactions are measured

Question 2

equation for reaction

Answer 2

CuSO4 (s) + aq –> CuSO4.5H2O

Question 3

6 stages for measuring enthalpy change for △H1

Answer 3

1. calorimeter setup= polystyrene cup in beaker
   2.weigh out 3.9-41g CuSO4 on 3dp balance and add to calorimeter
   3.measure out 25cm^3 distilled water in measuring cylinder and add to calorimeter
   4.record initial temp and start stopwatch. Record temp every 30s+stir continuously
   5.at 4 mins add CuSO4.5H2O but only record temp at 5 min. Record temp every 30 sec until 15 min
2. plot graph of temp against time. Draw 2 best fits and extrapolate them to determine △H at 4 min

Question 4

6 stages for measuring enthalpy change for △H2

Answer 4

1. calorimeter setup= polystyrene cup in beaker
   2.weigh out 6.1-6.2g CuSO4.5H2O on 3dp balance and add to calorimeter
   3.measure out 24cm^3 distilled water in measuring cylinder and add to calorimeter
   4.record initial temp and start stopwatch. Record temp every 30s+stir continuously
   5.at 4 mins add CuSO4(s)but only record temp at 5 min. Record temp every 30 sec until 15 min
2. plot graph of temp against time. Draw 2 best fits and extrapolate them to determine △H at 4 min