‘How does temperature effect the concentration of chlorate ions in bleach?’
The aim of this experiment was to investigate the optimum temperature storage conditions of bleach’s stored at different temperatures.
Chlorine bleaches are made by dissolving chlorine in sodium hydroxide solution. They have a number of uses as they are used to remove colors, whiten or disinfectant via oxidation. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing as they contain chlorate ions. Sodium Thiosulphate is used in the pH testing of bleach substances as it neutralizes the color-removing effect of the bleach and makes it feasible to test the pH of the bleach solution.
Data collection and Processing:
In this experiment we have been provided with bleach that has been stored at different temperatures-25, 35, 45, 55 and 650C for 3 weeks (the same volume of bleach and storage conditions have been followed for each sample, except for changing the temperature.)
Table for Chlorine Bleach stored at 250C (room temperature) Pipette Solutions: | H2SO4- 10cm2, KI- 10cm2, De-ionised water-10cm2 | Burette Solutions: | Sodium Thioshulphate | Indicator: | Starch – 2/3 drops | | Trail | 1 | 2 | 3 | 4 | | Trails: | 10 | 8.0 | 8.7 | 8.5 | 8.5 | | Burette Readings: | Initial | 0.00cm310.0cm2 | Difference – (final-initial)10.0cm3 | Final | | | Mean titre: | 8.42cm2 |
Table for Chlorine Bleach stored at 350C Pipette Solutions: | H2SO4- 10cm2, KI- 10cm2, De-ionised water-10cm2 | Burette Solutions: | Sodium Thioshulphate | Indicator: | Starch – 2/3 drops | | Trail | 1 | 2 | 3 | 4 | | Trails: | 6 | 8.0 | 6.0 | 6.1 | 6.2 | | Burette Readings: | Initial | 35.0cm3 | Difference – (final-initial)
20.5cm2 | Final | 13.5cm2 | | Mean titre: | 26.3cm2 |