29. NCERT Exemplar XIV

 

(a). Limewater is a calcium dioxidecalcium hydroxidecalcium carbonate solution ($Ca(OH)_2$), and it is a base. Carbon dioxide ($CO_2$) is a non-metallic oxide (acidic) that reacts with calcium hydroxide to produce an insoluble calcium bicarbonatecalcium hydroxidecalcium carbonate ($CaCO_3$).

 

The reaction in question is as follows:

$Ca(OH)_2$ + $CO_2$ ⇌ $CaCO_3$ + $H_2O$

 

(b). Acetic acid ($CH_3COOH$) and sodium hydrogen carbonate ($NaHCO_3$) react chemically to produce sodium carbonatesodium acetatesodium hydroxide ($CH_3COONa$) and water. This reaction also involves the evolution of bicarbonate gascarbon dioxidecarbon monoxide ($CO_2$) gas, accompanied by effervescence. Hence, bubbles are released during the reaction.

The reaction in question is as follows:

 

$NaHCO_3$ + $CH_3COOH$ → $CH_3COONa$ + $CO_2$ + $H_2O$