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प्रश्न
Turmeric and litmus are _________ acid-base indicators.
उत्तर
Turmeric and litmus are natural acid-base indicators.
APPEARS IN
संबंधित प्रश्न
- Both acids and bases change colour of all indicators.
- If an indicator gives a colour change with an acid, it does not give a change with a base.
- If an indicator changes colour with a base, it does not change colour with an acid.
- Change of colour in an acid and a base depends on the type of the indicator.
Which of these statements are correct?
What colours do the following indicators turn when added to an acid (such as hydrochloric acid)?
litmus
The property which is common between vinegar and curd is that they:
(a) have sweet taste
(b) have bitter taste
(c) are tasteless
(d) have sour taste
What colour will universal indicator show if you add it to the following substances?
(a) potassium hydroxide, pH = 12
(b) soda water, pH = 5
(c) sulphuric acid, pH = 2
A beaker of concentrated hydrochloric acid has a pH of 1. What colour will full range universal indicator turn if it is added to this beaker? Is it a strong or a weak acid?
State whether a solution is acidic, alkaline or neutral if its pH is:
(i) 9
(ii) 4
(iii) 7
(iv) 1
(v) 10
(vi) 3
A solution turns phenolphthalein indicator pink. The most likely pH of this solution will be:
(a) 6
(b) 4
(c) 9
(d) 7
A group of students measured the pH of some substances they found in their homes. Their results are given in the following table:
| Substance | pH | Substance | pH |
| Apples | 3.0 | Salt | 7.0 |
| Baking soda | 8.5 | Sugar | 7.0 |
| Black coffee | 5.0 | Toothpaste | 9.0 |
| Household ammonia | 12.0 | Vinegar | 3.0 |
| Lemon juice | 2.5 | Washing soda | 11.5 |
| Milk | 6.5 |
(a) What would the students have used to measure the pH?
(b) Which solution is the most acidic?
(c) Which solution is the most alkaline?
(d) Which solutions are neutral?
(e) Which solution can be used to treat wasp stings?
(f) Which solutions can be used to treat bee stings?
Name the acid present in vinegar.
Take a small beetroot vegetable and cut it into pieces. Boil them in hot water and filter the extract. Take two test tubes. Take sodium hydroxide solution in one test tube and vinegar or lemon juice in another test tube. Add beetroot extract slowly. Observe the colour change. What do you infer?
