Advertisements
Advertisements
प्रश्न
When phenolphthalein is added to NaOH, the colour of the solution will become _________.
- colourless
- red
- pink
- yellow
Advertisements
उत्तर
pink
When phenolphthalein is added to NaOH, the colour of the solution will become pink
APPEARS IN
संबंधित प्रश्न
Why should curd and sour substances not be kept in brass and copper vessels?
Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
What happens when an acid reacts with a metal?
On adding dilute hydrochloric acid to copper oxide powder, the solution formed is blue-green.
On the basis of the above reaction, what can you say about the nature of copper oxide?
What ions are present in the solutions of following substances? (write the symbols only)
Nitric acid
Define an acid and a base. Give two examples of each.
Hydrochloric acid reacts with a metal X to form a gas Y which burns with a 'pop' sound. Sodium hydroxide solution also reacts with the same metal X (on heating) to form the same gas Y.
Write the chemical equation of the reaction of metal X with (i) hydrochloric acid, and (ii) sodium hydroxide solution.
Write the chemical formula of soda ash?
Name the product formed when Cl2 and H2 produced during the electrolysis of brine are made to combine.
Complete and balance the following chemical equations:
`Ca(OH)_2 + Cl_2 ->`
Is PbO2 a base or not? Comment.
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.
Magnesium hydroxides are used for treating _______
Write any four physical properties of acids.
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?
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.
Acids present in fruits and vegetables are called ______ acids.
Solutions of acids conduct ______.
______ & ______ metals do not react with HCl or HNO3.
