Effect of carbon dioxide on the pH of water
Practical 3
Title: Effect of dissolved Carbon Dioxide on the pH of Water
Aim: To investigate the effect of dissolved carbon dioxide on the pH of water.
Hypothesis: The dissolved carbon dioxide will cause the water to turn acid, lowering the pH when carbon dioxide dissolves in water in which it forms carbonic acid (H2CO3).
Materials: Straws, distilled water, safety glasses, pH probe, computer, universal indicator, gloves, lab coats, measuring cylinder, data logger, printer, pH chart.
Substance of risk
Nature of risk
Safety Precaution
Weak carbonic acid solution
Slightly corrosive and might make contact with the eyes.
-Wear gloves and safety glasses.
Limewater (calcium hydroxide)
May be irritant to the skin and eyes
-Wear gloves, lab coat safety glasses.
-Wipe away any spills followed by washing of the contacted area.
-Wash hands after use.
Classware
May cause cuts
-Check any items for hair-like cracks before use; if so discard the item.
-Handle with care.
-Place on the centre of the bench.
Method:
Part A
1. Added 100mL of distilled water using a measuring cylinder into a 250mL beaker.
2. Placed the pH probe attached to data logger and computer, into a beaker of water and recorded the pH for 120 seconds (control exp).
3. In another beaker, added 100mL of distilled water using a measuring cylinder. Placed the probe attached to data logger and computer, into the beaker.
4. Using a straw blew continuously and gently into the water and recorded the pH for 120 seconds.
5. Repeated the experiment at least 5 times. Compared the results obtained and if similar results are obtained, the results can be said to be reliable.
6. To prove that exhaled air contained carbon dioxide blew into a beaker of limewater using a straw.
Part B
1. Filled a beaker with 100mL of water and added 3 drops of universal indicator into it.
2. Using a straw, carbon dioxide was exhaled into the water, noting the colour.
3. The above
Title: Effect of dissolved Carbon Dioxide on the pH of Water
Aim: To investigate the effect of dissolved carbon dioxide on the pH of water.
Hypothesis: The dissolved carbon dioxide will cause the water to turn acid, lowering the pH when carbon dioxide dissolves in water in which it forms carbonic acid (H2CO3).
Materials: Straws, distilled water, safety glasses, pH probe, computer, universal indicator, gloves, lab coats, measuring cylinder, data logger, printer, pH chart.
Substance of risk
Nature of risk
Safety Precaution
Weak carbonic acid solution
Slightly corrosive and might make contact with the eyes.
-Wear gloves and safety glasses.
Limewater (calcium hydroxide)
May be irritant to the skin and eyes
-Wear gloves, lab coat safety glasses.
-Wipe away any spills followed by washing of the contacted area.
-Wash hands after use.
Classware
May cause cuts
-Check any items for hair-like cracks before use; if so discard the item.
-Handle with care.
-Place on the centre of the bench.
Method:
Part A
1. Added 100mL of distilled water using a measuring cylinder into a 250mL beaker.
2. Placed the pH probe attached to data logger and computer, into a beaker of water and recorded the pH for 120 seconds (control exp).
3. In another beaker, added 100mL of distilled water using a measuring cylinder. Placed the probe attached to data logger and computer, into the beaker.
4. Using a straw blew continuously and gently into the water and recorded the pH for 120 seconds.
5. Repeated the experiment at least 5 times. Compared the results obtained and if similar results are obtained, the results can be said to be reliable.
6. To prove that exhaled air contained carbon dioxide blew into a beaker of limewater using a straw.
Part B
1. Filled a beaker with 100mL of water and added 3 drops of universal indicator into it.
2. Using a straw, carbon dioxide was exhaled into the water, noting the colour.
3. The above