Question

Fill in the blanks:
Most liquids that conduct electricity are solutions of acids, bases and _________.
A. salts
B. sugars
C. peppers
D. none of these

Answer 1

Hint: The liquids which can conduct electricity have free ions inside them which allow the conduction of electricity through them. The solutions of the conducting liquids have free ions which move to opposite electrodes when electricity is passed through the liquid.

Complete step-by-step answer:
Acids can be defined as those compounds which when dissolved in water give rise to hydrogen ions (\[{H^ + }\]).
For example: Hydrochloric acid (HCl), sulfuric acid (${H_2}S{O_4}$), nitric acid ($HN{O_3}$), etc.
Bases can be defined as those compounds which give rise to hydroxyl ions ($O{H^ - }$) when dissolved in water.
For example: Sodium hydroxide ($NaOH$), calcium hydroxide ($Ca{\left( {OH} \right)_2}$), etc.
When an acid reacts with a base, we obtain salt and water molecules. For example: When hydrochloric acid reacts with sodium hydroxide, we obtain sodium chloride which is a salt along with water as can be seen in the following reaction.
$HCl + NaOH \to NaCl + {H_2}O$
The salt gives rise to ions when dissolved in water; $N{a^ + }$ and $C{l^ - }$. Now when we pass electricity through such a solution through oppositely charged electrodes, the positive ions move towards the negative terminal while the negative ions move towards the positive terminals. The flow of these charges constitutes a current and hence, the liquid is able to conduct electricity through it.
Hence, the correct answer is option A.


Note: 1. For both acids and bases also, we have positive and negative ions which dissociate and move freely when dissolved in water. These freely moving charged molecules allow the conduction of electricity through acids and bases.
2. A solution can conduct electricity only if it contains charged entities. The sugars are covalent in nature and do not form free ions in liquid form and hence, cannot conduct electricity.