Question

Which of the following compounds will not undergo decomposition on passing electricity through aqueous solution?
(A) Sugar
(B) Sodium chloride
(C) Sodium bromide
(D) Sodium acetate

Answer 1

Hint: Ionic compounds are the compounds which are good conductors of electricity because on passing electricity through their aqueous solution, they dissociate into their respective ions.

Step-by-Step Explanation:
Sodium chloride is a salt which has the chemical formula $NaCl$. It is prepared by reaction of sodium hydroxide and hydrochloric acid. It is an ionic compound. When electricity is passed through aqueous solution of sodium chloride, the salt dissociates into sodium ions$N{a^ + }$ and chlorine ions $C{l^ - }$ .
Sodium bromide is bromide salt of sodium with the chemical formula $NaBr$. It is also an ionic compound. When electricity is passed through its aqueous solution, the salt dissociates into bromide ions $B{r^ - }$ and sodium ions $N{a^ + }$.
Sodium acetate is sodium salt of acetic acid with chemical formula $C{H_3}COONa$ . When acetic acid reacts with sodium hydroxide, sodium acetate is obtained. It is also an ionic compound. So when electricity is passed through its aqueous solution, the salt dissociates into acetate ions $C{H_3}CO{O^ - }$ and sodium ions $N{a^+ }$.
Sugar is a carbohydrate which contains aldehydic or ketonic group in hemi-acetal or hemi-ketal form. It is a covalent compound. So, when electricity is passed through its aqueous solution it does not dissociate into ions.
Hence except sugar sodium chloride, sodium bromide and sodium acetate decompose when electricity is passed through its aqueous solution as they are all ionic compounds.

Answer- The correct answer is A.

Note: Carbohydrates are optically active poly-hydroxy aldehydes or poly-hydroxy ketones. Sugar is classified into two types-
- Reducing sugar- which can be reduced into two or more components. Ex- maltose which can be broken into two molecules of glucose.
- Non-reducing sugar- which cannot be further broken into two components. Ex- glucose.