I also predict that when I add the acid and bases together they will react forming other chemicals as such: -
NaOH + HCl = H2O + NaCl
The sodium hydroxide and the hydrochloric acid will react together and produce water and sodium chloride.
2NaOH + H2SO4 = H2O + Na2SO4
The sodium hydroxide and the sulphuric acid react together and produce water and sodium sulphate.
Method
The apparatus was set up as shown.
Universal indicator was used to show firstly the acid and alkali and secondly that the neutralisation had taken place. 10ml of 0.15m NaOH was placed in a conical flask and after making sure that the tap on the burette was closed, 0.02m of HCl was placed into the burette. This was released slowly until the indicator turned green showing neutralisation had taken place. The test was repeated exactly but instead of HCl, H2SO4 with a molar of 0.1 was used in its place. The amount of acid used to neutralise the base was recorded in both cases. The type and volume of acid that was used in these tests were variable.
Safety
Normal laboratory safety conditions applied.
Other safety precautions that had been taken were goggles were worn to protect eyes, lab coats were worn to protect clothing and distilled water was close by for rinsing any spillages.
Results
The results in volume shown are the amount of each chemical used to achieve neutralisation and change the universal indicator green.
Chemical Molar Volume Colour
(ml) (Universal indicator)
NaOH 0.15 10 Purple
HCl 0.02 78 Red
Chemical Molar Volume Colour
- (universal indicator)
NaOH 0.15 10 Purple
H2SO4 0.1 5.6 Red
Conclusion
Using 10ml 0.15m of sodium hydroxide and adding 78ml of 0.02m hydrochloric acid neutralisation took place. The red indicator in the acid and the purple indicator in the alkali turned to green showing this was the case. This reaction created a solution of water and sodium chloride.
Using 10ml 0.15 of sodium hydroxide and adding 5.6ml of 0.1m sulphuric acid neutralisation took place. Again the red indicator in the acid and the purple indicator in the alkali turned green showing this was the case. This reaction created a solution of water and sodium sulphate.
Evaluation
The titration process was successfully completed in both experiments. Although my prediction for the first experiment was very close to the result, whereby I predicted a result of 75ml and the amount used was actually 78ml of acid. The prediction and result for my second experiment was not close, predicting 15ml when only 5.6ml of acid were needed to complete a titration. This could have been due to the fact that there were two hydrogen ions in every molar of sulphuric acid making the acid stronger and ionising over two steps. The more hydrogen ions an acid produces the stronger it is. Therefore for every 1 unit of acid needed two units of alkali would be needed. This experiment was done accurately and correctly. It also went very well.
