✓ Board-verified
Science · 2024 · 3 marks
CBSE 2024 · Region 2 · Set 1 · Q27
It is observed that Calcium on reaction with water floats on its surface. Explain why it happens. Also write a balanced chemical equation for the…
It is observed that Calcium on reaction with water floats on its surface. Explain why it happens. Also write a balanced chemical equation for the reaction that occurs. What happens when the aqueous solution of the product of this reaction reacts with Carbon dioxide gas ? Write a balanced chemical equation for the reaction.
Marking-scheme solution
Bubbles of hydrogen gas formed stick to the surface of calcium and make it lighter than water.
\[\mathrm{Ca}(s)+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow \mathrm{Ca}(\mathrm{OH})_{2}\left(\mathrm{aq}+\mathrm{H}_{2}(g)\right.
\]
The solution formed turns milky.
\[\mathrm{Ca}(\mathrm{OH})_{2}(\mathrm{aq})+\mathrm{CO}_{2}(\mathrm{~g}) \longrightarrow \mathrm{CaCO}_{3}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})
\]
All Metals and Non-metals questions2024 question paperNCERT solutions: Metals and Non-metalsPractice Metals and Non-metals →
More from Metals and Non-metals
- (i) It is observed that covalent compounds are bad conductors of electricity. Give reason. (ii) Carbon can neither form C^4+ cation nor C^4- anion.…2023
- A metal, M, displaces iron from aqueous solution of ferrous sulphate but fails to do so in case of aqueous solution of aluminium sulphate. The metal…2025
- Sodium metal is stored under kerosene oil. Why? Some metal oxides are soluble in water. What are the aqueous solutions of these oxides called? Write…2024
- List two advantages of adopting the atomic number of an element as the basis of classification of elements in the Modern Periodic Table. Write the…2022
- Consider the following organic compounds: (i) (ii) Name the functional group present in their compounds. Write the general formula for the compounds…2022
- Attempt either or: (i) Write one example each of one metal that is so soft that it can be cut with a knife, and one non-metal that is a good…2026
- Cinnabar is an ore of a metal 'X'. When this ore is heated in air, it is first converted into oxide of 'X' (XO) and then reduced to metal 'X' on…2025
- Which of the following is an alloy of copper and tin?2024
CBSE Class 10 Science past-paper question from the 2024 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.