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प्रश्न
Phenolphthalein is a synthetic type of indicator.
पर्याय
True
False
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उत्तर
Phenolphthalein is a synthetic type of indicator - True
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संबंधित प्रश्न
From which plant is litmus paper or litmus solution obtained?
- Moss
- Rose
- Hibiscus
- Lichen
Dry HCl gas does not change the colour of dry blue litmus paper. Why?
How is the concentration of hydronium ions (H3O+) affected when the solution of an acid is diluted?
A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains ______.
What happens when an acid reacts with a metal hydrogencarbonate? Write equation of the reaction which takes place.
A first-aid manual suggests that vinegar should be used to treat wasp stings and baking soda for bee stings. What does this information tell you about the chemical nature of:
- wasp stings?
- bee stings?
What is the chemical formula of washing soda?
What happens when a solution of sodium hydrogencarbonate is heated? Write equation of the reaction involved.
Answer the following question.
Identify the acid and base which form sodium hydrogen carbonate. Write the chemical equation in support of your answer. State whether this compound is acidic, basic, or neutral. Also, write its pH value.
A solution of NaCl
(i) will turn red litmus blue
(ii) will turn pH paper green
(iii) will turn blue litmus red
(iv) will not affect litmus
The table given below shows the reaction of a few elements with acids and bases to evolve Hydrogen gas.
| Element | Acid | Base |
| A |
✗
|
✗ |
| B |
✓
|
✓ |
| C | ✓ | ✗ |
| D | ✓ | ✓ |
Which of these elements form amphoteric oxides?
Which of the following statements is not correct?
Name the acid present in ant sting and give its chemical formula. Also give the common method to get relief from the discomfort caused by the ant sting.
In the following schematic diagram for the preparation of hydrogen gas as shown in the figure, what would happen if following changes are made?
- In place of zinc granules, same amount of zinc dust is taken in the test tube
- Instead of dilute sulphuric acid, dilute hydrochloric acid is taken
- In place of zinc, copper turnings are taken
- Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated.
Copper or brass cooking vessels are coated with tin metal. Why?
“All acids contain one or more hydrogen atoms, but not all substances containing hydrogen are acids.” Support this statement with examples.
Two salts 'X' and 'Y' are dissolved in water separately. When phenolphthalein is added to these two solutions, the solution 'X' turns pink and the solution 'Y' does not show any change in colour, therefore 'X' and 'Y' are:
