question_answer

Write balanced chemical equations for the following statements:

(i) NaOH solution is heated with zinc granules.

(ii) Excess of carbon dioxide gas is passed through lime water.

(iii) Dilute sulphuric acid reacts with sodium carbonate.

(iv) Egg shells are dropped in hydrochloric acid.

(v) Copper (II) oxide reacts with dilute hydrochloric acid.

Answer:

(i) \[\underset{\begin{smallmatrix}  \text{  Sodium } \\  \text{hydroxide} \end{smallmatrix}}{\mathop{2NaOH(aq)}}\,+\underset{\text{Zinc}}{\mathop{Zn(s)}}\,\xrightarrow{\Delta }\underset{\text{Sodium zincate}}{\mathop{N{{a}_{2}}Zn{{O}_{2}}(aq)}}\,+\underset{\text{Hydrogen}}{\mathop{{{H}_{2}}(g)}}\,\]

(ii) \[\underset{\text{Lime water}}{\mathop{Ca{{(OH)}_{2}}}}\,+C{{O}_{2}}\to \underset{\begin{smallmatrix}  \text{Calcium carbonate} \\  \text{     (white ppt}\text{.)} \end{smallmatrix}}{\mathop{CaC{{O}_{3}}(s)}}\,+{{H}_{2}}O\]

\[CaC{{O}_{3}}(s)+\mathrm{ }C{{O}_{2}}(g)+\mathrm{ }{{H}_{2}}O(l)\to \underset{\begin{smallmatrix}  \text{       Calcium hydrogen} \\  \text{carbonate (Soluble in water)} \end{smallmatrix}}{\mathop{Ca(HC{{O}_{3}})(aq)}}\,\]

(iii) \[{{H}_{2}}S{{O}_{4}}(dil.)+\mathrm{ }N{{a}_{2}}C{{O}_{3}}(s)\to \underset{Sodium\text{ }sulphate}{\mathop{N{{a}_{2}}S{{O}_{4}}}}\,+C{{O}_{2}}+{{H}_{2}}O\]

(iv) \[\underset{\begin{smallmatrix}  \text{Egg shell contains} \\  \text{calcium carbonate} \end{smallmatrix}}{\mathop{CaC{{O}_{3}}(s)}}\,+\mathrm{ }2HCl\to CaC{{l}_{2}}\mathrm{+}{{H}_{2}}O+C{{O}_{2}}\]

(v) \[CuO(s)+\mathrm{ }2HCl(aq)\to \underset{\begin{smallmatrix}  \text{Copper chloride} \\  \text{   (blue green)} \end{smallmatrix}}{\mathop{CuC{{l}_{2}}(aq)}}\,+{{H}_{2}}O(l)\]