NCERT Solution for Class 10 Science Chapter 1
Chemical Reactions and Equations
Intext Questions
Page No-10
Questions No-1
(i) Name the substance ‘X’ and write its formula.
(ii) Write the reaction of the substance ‘X’ named in (i) above with
water.
(i) The substance used for whitewashing is calcium oxide, commonly known as quicklime. Its chemical formula is CaO.
(ii) The reaction of calcium oxide (quicklime) with water is an exothermic reaction, and it produces calcium hydroxide, commonly known as slaked lime. The balanced chemical equation for this reaction is:
CaO + H₂O → Ca(OH)₂
In words, quicklime reacts with water to form calcium hydroxide.
(i) The chemical name of substance, which is used for white washing is Calcium oxide. Its common name is lime or quick lime.
The chemical formula of Calcium Oxide is CaO.
(ii) 𝐶𝑎𝑂+𝐻₂𝑂 → 𝐶𝑎(𝑂𝐻)₂
When calcium oxide reacts with water it forms calcium hydroxide. Calcium hydroxide is also known as slaked lime.
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO.
(ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime)
𝐶𝑎𝑂+𝐻₂𝑂 → 𝐶𝑎(𝑂𝐻)₂