ADITYA VIDYASHRAM RESIDENTIAL SCHOOL, PUDUCHERRY
CLASS X CHEMISTRY PRACTICALS 2023-2024
pH VALUE OF SOLUTIONS
Expt. No. 2A
Date:
OBJECTIVE
To find the pH of the following samples by using pH paper / Universal Indicator.
1. Dilute Hydrochloric acid.
2. Dilute NaOH solution.
3. Dilute Ethanoic acid solution.
4. Lemon juice.
5. Water.
6. Dilute Sodium bicarbonate solution.
PROCEDURE
1. Take six strips pH paper and place them on a glazed tile. Mark them 1 to 6.
2. Take the test solutions in separate test tubes. Dissolve the solid substance by adding
distilled water to it. Label the test tubes.
3. Now, place a drop of the test solution on one strip of the pH paper with the help of a fine
dropper or glass rod. Use a fresh dropper for each test solution.
4. Observe the colour produced and match it with the different colour shades of the standard
colour pH chart.
5. Note down the colour of the pH from the colour chart that matches most closely with the
colour produced on the pH paper.
6. Similarly, find the pH value of the remaining samples by using a fresh strip of pH paper
and a separate glass rod or fine dropper for each one.
OBSERVATIONS
S. No. Sample solution Colour produced on pH paper Approximate pH Inference
1 Dil.HCl Red 1 Strong Acid
2 Dil. NaOH Purple 14 Strong Base
3 Dil. Ethanoic acid Yellow 3 Weak Acid
4 Lemon juice Orange 2 Acidic
5 Water Green 7 Neutral
6 Dil. Sodium bicarbonate sol. Blue 9 Weak Base
PRECAUTIONS
1. Use only the standard colour chart supplied with the pH paper for assessing the pH
value.
2. Keep the pH strips away from chemical fumes.
3. Either use fresh fine dropper or glass rod for each different sample, or wash the dropper
or rod well with water every time.
