The Effect of Dissolved Carbon Dioxide on Ph
Investigating pH
Aim: To demonstrate dissolved carbon dioxide changing the ph level of substances.
Materials:
* 2 beakers * 2 straws * Stop watch * Distilled water * Lime water * Litmus Paper
Method:
1. Pour 100ml of Distilled water into the first beaker, and label said beaker.
2. Pour 100ml of Lime water into the second, also Label beaker.
3. Test the two liquids with litmus paper and note the ph level, before any carbon dioxide has been introduced.
4. Place a straw in each beaker.
5. One person will blow into the first beaker for a set period of time, while the other times, monitors and controls the time spent blowing.
6. Then test and note the ph of the liquid which has been blown into.
7. Repeat steps 5 and 6 on the other liquid, making sure that the amount of time spent blowing is equal for both.
8. Continue to repeat steps 5, 6 and 7 and note any changes in ph.
* Acids have more “H+” Hydrogen ions. * An Alkaline has a greater number of “OH-” Hydroxide ions. * A neutral solution will have equal numbers of H+ and OH-.
Accumulated time: 0 sec 10 sec 20 sec 38 sec 61 sec 84 sec 107 sec
Individual exhale time: 0 sec +10 sec +10 sec +18 sec +23 sec +23 sec +23 sec pH of Distilled water 7 7 7 7 7 7 7 pH of Lime Water 14 14 14 10 9 8 7
Distilled water: Although the distilled water remained within the PH of 7, the indicator showed a slight change in colour from a light yellow to a darker more orange yellow. This suggests that the pH of the distilled water was slowly changing from a pH of 7 to a PH of 6. i.e. becoming more acidic. More H+ ions then before
Lime Water: As shown in the results, exhaling into the lime water had a significant change on its PH; neutralising it from a PH of 14 (Strong Base) to a PH of 7 (neutral). More H+ ions then before
Aim: To demonstrate dissolved carbon dioxide changing the ph level of substances.
Materials:
* 2 beakers * 2 straws * Stop watch * Distilled water * Lime water * Litmus Paper
Method:
1. Pour 100ml of Distilled water into the first beaker, and label said beaker.
2. Pour 100ml of Lime water into the second, also Label beaker.
3. Test the two liquids with litmus paper and note the ph level, before any carbon dioxide has been introduced.
4. Place a straw in each beaker.
5. One person will blow into the first beaker for a set period of time, while the other times, monitors and controls the time spent blowing.
6. Then test and note the ph of the liquid which has been blown into.
7. Repeat steps 5 and 6 on the other liquid, making sure that the amount of time spent blowing is equal for both.
8. Continue to repeat steps 5, 6 and 7 and note any changes in ph.
* Acids have more “H+” Hydrogen ions. * An Alkaline has a greater number of “OH-” Hydroxide ions. * A neutral solution will have equal numbers of H+ and OH-.
Accumulated time: 0 sec 10 sec 20 sec 38 sec 61 sec 84 sec 107 sec
Individual exhale time: 0 sec +10 sec +10 sec +18 sec +23 sec +23 sec +23 sec pH of Distilled water 7 7 7 7 7 7 7 pH of Lime Water 14 14 14 10 9 8 7
Distilled water: Although the distilled water remained within the PH of 7, the indicator showed a slight change in colour from a light yellow to a darker more orange yellow. This suggests that the pH of the distilled water was slowly changing from a pH of 7 to a PH of 6. i.e. becoming more acidic. More H+ ions then before
Lime Water: As shown in the results, exhaling into the lime water had a significant change on its PH; neutralising it from a PH of 14 (Strong Base) to a PH of 7 (neutral). More H+ ions then before