Solid calcium oxide was taken in a container and water was added slowly to it.
(i) State two observations made in the experiment.
(ii) Write the balanced chemical equation of this reaction.
or
Write balanced chemical equations for the following reactions `:`
(a) dilute sulphuric acid reacts with aluminum powder.
(b) dilute hydrochloric acid reacts with sodium carbonate.
(c) Carbon dioxide is passed through lime water.

Explanation

(i) Solid calcium oxide was taken in a container and water added to it.
Observation `:`
The mixture produces a hissing sound.
The beaker feels to be quite hot.
(ii) `underset("(lime)")underset("Calcium oxide")(CaO(s))+H_(2)O rarr underset("(slaked flame)")underset("Calcium hydroxide")(Ca(OH)_(2))+"Heat"`
(a) `2Al(s) +3H_(2)SO_(4)(aq)rarr underset("Aluminium sulphate")(Al_(2)(SO_(4))_(3)(aq))+3H_(2)uarr`
(b) `underset("Sodium carbonate")(Na_(2)CO_(3)(s)) +2HCl(aq) rarr 2NaCl(aq) +CO_(2)+H_(2)O`
(c ) `CO_(2)(g) +underset("Lime water")(Ca(OH)_(2)(aq))rarr underset("(White ppt makes lime water milky)")(CaCO_(3)(s))+H_(2)O`