Ph Indicator Experiment
Red Cabbage Indicator
Aim – To create a pH indicator out of a red cabbage solution and to construct a basic pH scale to determine the pH of unknown solutions.
Materials -
• red cabbage leaves
• 250 mL beaker
• hotplate or Bunsen burner, tripod, gauze mat and bench mat
• 10 test-tubes – equal size
• test-tube rack
Methods -
Part A: Making the indicator 1. Tear up one or two red cabbage leaves, and place them in the beaker with enough water so that the cabbage is just covered. 2. Heat the beaker until the water is gently boiling. Continue to boil until the water has been strongly coloured red by the cabbage leaves. Boil for approximately ten minutes, depending on color of water. 3. Allow to cool and then decant the liquid into a small …show more content…
Results -
Chemical added to indicator Color Estimated pH Acid or Base
Test Tube A (Soft Drink): Light pink 3-6 Acid
Test Tube B (lemon juice): Pinkish Red 2-4 Acid
Test Tube C (Antacid Tablet): Light purple 6-5 Acid
Test Tube D (ammonia solution): Green 9-11 Base
Test Tube E (Sodium Carbonate Solution): Dark Green 8-10 Base
Test Tube F (Sugar Solution): Purple 7 Neutral
Our results showed the clear color change as pH increased, transitioning from pink to purple to green to yellow. This develops a basic scale for us to base observations on, as a benchmark was developed. The pH of the substances in part C were unknown, and as such color changes were observed, allowing us to estimate the pH of the substances (see discussion). However, based on the scale, it is agreeable that the pinker substances in Part C were acidic, the greener substances were alkaline and the purple substances were neutral.
Further research shows that
Test Tube A (lemonade) has an approximate pH of 2.6 (“The Unsweetened Truth”)
Test Tube B (Lemon Juice) has an approximate pH of 2.0 (“Acids, Bases and the pH scale”)
Test Tube C (Antacid Tablets) have an approximate pH of 8 (depending on Antacid). (Dr.
Aim – To create a pH indicator out of a red cabbage solution and to construct a basic pH scale to determine the pH of unknown solutions.
Materials -
• red cabbage leaves
• 250 mL beaker
• hotplate or Bunsen burner, tripod, gauze mat and bench mat
• 10 test-tubes – equal size
• test-tube rack
Methods -
Part A: Making the indicator 1. Tear up one or two red cabbage leaves, and place them in the beaker with enough water so that the cabbage is just covered. 2. Heat the beaker until the water is gently boiling. Continue to boil until the water has been strongly coloured red by the cabbage leaves. Boil for approximately ten minutes, depending on color of water. 3. Allow to cool and then decant the liquid into a small …show more content…
Results -
Chemical added to indicator Color Estimated pH Acid or Base
Test Tube A (Soft Drink): Light pink 3-6 Acid
Test Tube B (lemon juice): Pinkish Red 2-4 Acid
Test Tube C (Antacid Tablet): Light purple 6-5 Acid
Test Tube D (ammonia solution): Green 9-11 Base
Test Tube E (Sodium Carbonate Solution): Dark Green 8-10 Base
Test Tube F (Sugar Solution): Purple 7 Neutral
Our results showed the clear color change as pH increased, transitioning from pink to purple to green to yellow. This develops a basic scale for us to base observations on, as a benchmark was developed. The pH of the substances in part C were unknown, and as such color changes were observed, allowing us to estimate the pH of the substances (see discussion). However, based on the scale, it is agreeable that the pinker substances in Part C were acidic, the greener substances were alkaline and the purple substances were neutral.
Further research shows that
Test Tube A (lemonade) has an approximate pH of 2.6 (“The Unsweetened Truth”)
Test Tube B (Lemon Juice) has an approximate pH of 2.0 (“Acids, Bases and the pH scale”)
Test Tube C (Antacid Tablets) have an approximate pH of 8 (depending on Antacid). (Dr.