Common salt is a very important chemical compound for our daily life. It's chemical name is sodium chloride and it is used as a raw material in the manufacture of caustic soda, washing soda, baking soda etc. It is also used in the preservation of pickles, butter, meat etc.

(i) Name the acid and the base from which common salt can be obtained.

(ii) State the nature (acidic/basic/neutral) of sodium chloride. Give reason for the justification for your answer.

(iii) (A) What happens when electric current is passed through an aqueous solution of sodium chloride (called brine)? Name the products obtained along with the corresponding places in the electrolytic cell where each of these products is obtained.

OR

(iii) (B) How is washing soda obtained from sodium chloride? Give chemical equation of the reactions involved in the process.

(i) Sodium chloride can be obtained from hydrochloric acid (HCl) and sodium hydroxide (NaOH). The reaction is as follows: NaOH + HCl $\rightarrow$ NaCl + H2O (ii) Sodium chloride is neutral in nature. This is because it is the salt of a strong acid (HCl) and a strong base (NaOH). (iii) (A) When electric current is passed through an aqueous solution of sodium chloride (brine), the following reactions occur: At the anode (positive electrode): 2Cl- $\rightarrow$ Cl2 + 2e- At the cathode (negative electrode): 2H2O + 2e- $\rightarrow$ H2 + 2OH- The products obtained are chlorine gas (Cl2) at the anode and hydrogen gas (H2) at the cathode. The sodium hydroxide (NaOH) solution is obtained at the cathode. OR (iii) (B) Washing soda (sodium carbonate) is obtained from sodium chloride through the Solvay process. The chemical equation for the reaction is: NaCl + NH3 + CO2 + H2O $\rightarrow$ NaHCO3 + NH4Cl The sodium bicarbonate (NaHCO3) is then heated to produce sodium carbonate (Na2CO3): 2NaHCO3 $\rightarrow$ Na2CO3 + H2O + CO2