Question

07
(6) What happens when powdered chalk is added to a test
tube containing dilute hydrochloric acid? Explain with
the help of a balanced chemical reaction
(ii) What change is observed when the evolved gas is passed
through lime water?
(iii) What will happen if excess of the evolved gas is passed
through lime water?
Why dry HCl does not conducts electricity?
08​

Answer 1

ANSWER

Reaction involved-

$CaCO _{3} +2HCl=CaCl _{2} +CO _{2} +H_{2} O$

The evolved gas is carbon dioxide which when passes through lime water turns it milky.

$Ca(OH) _{2}+CO _{2}=H _{2} O+CaCO _{3}$ ⇐ due to formation of this compound

when excess $CO_{2}$ is passed

$CaCO_{3}+H_{2} O+CO_{2}=Ca(HCO_{3})_{2}$

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Bicarbonate is formed which again clears the solution.