Question 1 Page 10 - Chapter 1 Class 10 - Chemical Reactions and Equations

Last updated at August 12, 2026 by

A solution of a substance ‘X’ is used for white washing.

(i) Name the substance ‘X’ and write its formula.

(ii) Write the reaction of the substance ‘X’ named in (i) above with water.

 

Answer

(i) We know that slaked lime (Ca(OH) 2 ) is used for whitewashing .

 

The solution of slaked lime (Ca(OH) 2 ) is formed by reaction of Quicklime (CaO) and Water (H 2 O).

 

Hence, the substance ‘X’ is Calcium Oxide / Quicklime and its formula is CaO .

 

(ii) The reaction of ‘X’ with water is given as 


CaO(s) + H 2 O(l) → Ca(OH) 2 (aq)

Calcium Oxide Reaction-Teachoo-01.jpg

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