Question

Q15)Write the material required,procedure and precautions to investigate whether all compounds containing hydrogen are acidic or not (4 marks)​

Answer 1

Answer:

Aim:

Finding the pH of the following samples by using pH paper/universal indicator:

• Dilute hydrochloric acid
• Dilute sodium hydroxide solution
• Dilute ethanoic acid solution
• Lemon juice
• Water
• Dilute hydrogen carbonate solution

Materials Required:

• Test tubes
• test tube stand
• droppers or glass rod
• pH paper
• standard colour chart
• glazed white tile and samples of dil. HCL
• dil. ethanoic acid (vinegar)
• lemon juice
• distilled water and dil. sodium bicarbonate solution.

Procedure:

• Take the given solutions in separate test tubes marked as A ,B,C,D,E and F and keep them in the test tube stand.
• Take six strips of pH paper and place them on a glazed white tile.
• Using a dropper or a glass rod , place a drop of the test solutio. on the pH paper.
• Note the colur developed on the pH paper and compare it with the colur chart of the pH paper.
• Record the pH value corresponding to the colour.
• Similarly, using a fresh dropper each time , perform the experiment with the remaining test samples using afresh strip of pH paper.
• Record your observations.
• For using universal indicator, add a few drops of universal indicator to each of the test tubes with the test solutions.
• Note the colour of each solution and compare it with the colour on the indicator bottle.
• Record your observations.

Precautions:

1. Mark the test tubes carefully.
2. Use distilled water for preparing solutions.
3. Use only standard colour charts supplied with the pH paper for assessing the pH value.
4. Do not touch the pH paper with unclean and wet hands.
5. Keep the pH paper away from chemical fumes.
6. Do not touch or taste the solutions.
7. Clean the glass rod/dropper properly before reusing.
8. Do not waste pH paper.

Explanation:

I hope it will help u .

You can make changes in the replacement of words like pH paper,etc. , if it doesn't match with your question.