When ethanoic acid reacts with sodium hydrogencarbonate, a salt X is formed and a gas Y is evolved.

(a) Identify X and Y. Write chemical equation of reaction involved.


(b) Describe an activity and draw the diagram of the apparatus to prove that the evolved gas is the one which you have named.


OR


Look at Figure and answer the following questions.



(a) What change would you observe in tube B containing calcium hydroxide solution


(b) Write the reaction involved in test tubes A and B respectively


(c) If ethanol is given instead of acetic acid, would you expect the same change?


(d) How can a solution of lime water be prepared in the laboratory?

(a) X is Sodium ethanoate and Y is CO2. The reaction is as follows:


CH3COOH + NaHCO3 → CH3COONa + CO2 +H2O


 


(b) Take NaHCO3 in a test tube and add 2ml of ethanoic acid. CO2 is evolved with brisk effervescence. Pass the gas through freshly prepared lime water. The lime water turns milky. The apparatus is as follows:


 



 


OR


 


(a) It will turn milky due to the formation of CaCO3 in reaction with CO2.


 


(b) The reaction involved in test tube A is as follows:


 


2CH3COOH + Na2CO3 → 2CH3COONa + CO2 + H2O


 


The reaction involved in test tube B is as follows:


 


CO2 + Ca(OH)2 → CaCO3 + H2O


 


(c) No reaction will take place since ethanol is weakly acidic and cannot react with Na2CO3 to give CO2 gas.


 


(d) Lime water is prepared by the reaction of calcium oxide (Quick lime) with water followed by the decantation or filtering of supernatant liquid.


 


CaO + H2O → Ca(OH)2


 

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