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प्रश्न
What happens when calcium reacts with water? Write the chemical equation of the reaction of calcium with water.
Write a balanced equation for the reaction of the following:
Calcium with water
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उत्तर
When calcium reacts with water, it forms calcium hydroxide and hydrogen gas. Due to the formation of hydrogen bubbles that stick to the surface of calcium, it starts floating on water.
\[\ce{Ca_{(s)} + 2H2O_{(l)} -> Ca(OH)2_{(aq)} + H2_{(g)}}\]
Notes
Students should refer to the answer according to their questions.
संबंधित प्रश्न
‘E’ is an element which reacts with oxygen to form an oxide E2O. An aqueous solution of E2O turns red litmus blue, so:
i. What is the nature of oxide E2O ?
ii. Write the name of element ‘E’.
Write equations for the reactions of calcium and potassium with water.
Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.
| Metal | Iron (II) sulphate | Cooper (II) sulphate | Zinc sulphate | Silver nitrate |
| A | No reaction | Displacement | ||
| B | Displacement | No reaction | ||
| C | No reaction | No reaction | No reaction | Displacement |
| D | No reaction | No reaction | No reaction | No reaction |
Use the Table above to answer the following questions about metals A, B, C and D.
- Which is the most reactive metal?
- What would you observe if B is added to a solution of copper (II) sulphate?
- Arrange the metals A, B, C and D in the order of decreasing reactivity.
Write the electron-dot structures for sodium, oxygen and magnesium.
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Name the metal which has been placed at the top of the reactivity series.
Name the metal which has been placed just below copper in the reactivity series.
How would you show that silver is chemically less reactive than copper?
Complete and balance the following equation:
\[\ce{Na + O2 ->}\]
With the help of examples, describe how metal oxides differ from non-metal oxides.
Which of the following elements would yield a neutral oxide?
Na, S, C, K, H
What type of oxides are formed when metals combine with oxygen? Explain with the help of an example.
Give one example, with equation, of the displacement of hydrogen by a metal from an acid.
Name two metals (other than zinc and iron) which can displace hydrogen from dilute hydrochloric acid?
Write the equation for the reaction of:
Iron with dilute hydrochloric acid.
Name the products formed in the given case. Also indicate the physical states of all the substances involved.
The elements whose oxides can turn litmus solution blue are ______.
Which one of the following four metals would be displaced from the solution of its salt by the other three metals?
Arrange the following metals in the increasing order of their reactivities:
Copper, Zinc, Aluminium, and Iron
Write the chemical equation for the following reaction:
Cinnabar is heated in the presence of air.
Why is acidified water considered to be a good conductor of electricity?
