I think that if there are more NaOH particles in mixing with the HCL particles more collisions will happen and more heat will be produce. I also think that the more H2O I add the less heat will be produced, as this will reduce the concentration of NaOH and HCL.
Variables
Independent: I am going to change to concentration of HCL and the volume of water I am adding each time.
Dependant: I am going to measure the heat produced before, during and after I mix the HCL, NaOH and the H2O.
Controlled: I am going to keep the concentration of NaOH the same throughout these experiments.
Diagram
Apparatus
I am going to use apparatus in these experiments that will help it be accurate, they will be:
Conical flasks to hold the measured out volumes of HCL, H2O and NaOH. I will also use the conical flasks to mix the solutions in and I will read the temperatures when the solutions are being mixed inside these conical flasks.
I will use a thermometer to measure the temperature before, during and after the experiment. I will use three different burettes to hold the solutions in and to accurately measure out the solutions for increased accuracy.
Method
- Set up the three burettes, one with HCL, one with H2O and the other with NaOH
- Collect all three needed volumes of the three solutions in three different burettes.
- Measure initial temperature of the solutions and record it.
- Add all three solutions together and stir
- Carefully watch the thermometer and record the peak temperature of the reaction.
- Repeat the same experiment twice for added accuracy each time cleaning out the conical flasks.
- You should have to do ten experiments in all.
Safety
- I was very careful doing these experiments not to drop or spill any of the solutions.
- I took extra care when handling expensive apparatus like the burettes and the thermometer
- All desks were cleared and stools and bags were placed under the benches.
- I took of my blazer and tucked in my tie so that it would not dangle in my way when I was doing the experiments.
Results
Here is a copy of my blank results table:
Calculations
Moles of HCL: (moles = concentration x volume)
- 2 x 0.025=0.05 moles
- 2 x 0.02=0.04 moles
- 2 x 0.015=0.03 moles
- 2 x 0.01=0.02 moles
- 2 x 0.05=0.01 moles
Concentration of HCL: (concentration = moles / volume in litres)
- 0.05 25=2 moles/litres
- 0.04 25=1.6 moles/litre
- 0.03 25=1.2 moles/litre
- 0.02 25=0.8 moles/litre
- 0.01 25=0.4 moles/litre
Temperature rise:
- 25-19=6 25-19=6
- 23-18=5 24-18=6
- 24-18=6 24-18=6
- 23-19=4 23-19=4
- 21-19=2 21-19=2
Average temperature rise:
- 6+6=12 12 2=6
- 5+6=11 11 2=5.5
- 6+6=12 12 2=6
- 4+4=8 8 2=4
- 2+2=4 4 2=2
Results
All temperatures are in degrees Celsius
Conclusion
From the evidence (results in my table) I can conclude that the higher the concentration of HCL the more heat is produced when mixed with NaOH. For example when the concentration of 25 mls of HCL was 2 moles/litre and this was mixed with 2 moles/litre of NaOH the average temperature rise was 6 degrees Celsius compare to when the concentration was the same for NaOH as it was and it was mixed with a weaker solution of HCL of only 0.4moles/litre the average temperature rise was only 2 degrees Celsius.
I can also conclude that my prediction was right. I can say that prediction was accurate because of the follow reason. The more particles in the HCL, the faster the reaction would be because there are more particles to hit of each other, then there would be more of a reaction and all these particles would produce more heat when reacting.