Question

Which of the following is an example of strong electrolyte? (This question has multiple correct options)
${\text{A}}{\text{.}}$ ${\text{N}}{{\text{H}}_4}{\text{OH}}$ solution
${\text{B}}{\text{.}}$ NaOH solution
${\text{C}}{\text{.}}$ ${\text{C}}{{\text{H}}_3}{\text{COONa}}$ solution
${\text{D}}{\text{.}}$ HCN solution

Answer 1

Here, we will proceed by defining electrolytes in chemistry. Then, we will discuss when electrolyte is referred to as strong electrolyte and when as weak electrolyte. Finally, we will discuss whether the compounds given in options are electrolytes or not.

Complete answer:
Chemically, electrolytes are substances that become ions in solution and acquire the capacity to conduct electricity. The strength of an electrolyte, whether it is a strong electrolyte or a weak electrolyte, depends on the substance's ability to form ions by dissociation (or ionization). A strong electrolyte has a high degree of dissociation (ionisation) in solution whereas a weak electrolyte has a low degree of dissociation (ionisation) in solution.
${\text{N}}{{\text{H}}_4}{\text{OH}}$ solution: This solution is a weak electrolyte (base) because it is partially ionised in water and produce a small amount of hydroxide ions (${\text{O}}{{\text{H}}^ - }$ ions)
${\text{N}}{{\text{H}}_4}{\text{OH (aq) }} \to {\text{ N}}{{\text{H}}_4}^ + + {\text{O}}{{\text{H}}^ - }$
It does not act as acids because${\text{N}}{{\text{H}}_4}^ +$ is stable in water. It does not dissociate in water to give ${{\text{H}}^ + }$ ions which are responsible for the acidic nature.
NaOH solution: When sodium hydroxide (NaOH) is dissolved in water, it completely dissociates into sodium and hydroxide ions. Because aqueous sodium hydroxide exists entirely as ions in solution, it is referred to as a strong electrolyte (base).
${\text{NaOH (aq) }} \to {\text{ Na}} + {\text{O}}{{\text{H}}^ - }$
${\text{C}}{{\text{H}}_3}{\text{COONa}}$ solution: Sodium acetate (${\text{C}}{{\text{H}}_3}{\text{COONa}}$) is a salt of weak acid and strong base. It is formed by the reaction of acetic acid and sodium hydroxide. Since, it is salt so when it will completely dissolve in water and hence act as a strong electrolyte.
${\text{C}}{{\text{H}}_3}{\text{COONa (aq) }} \to {\text{ N}}{{\text{a}}^ + } + {\text{C}}{{\text{H}}_3}{\text{CO}}{{\text{O}}^ - }$
HCN solution: Hydrogen cyanide (HCN) is a weak electrolyte because when it is dissolved in water, it does not undergo complete dissociation (or ionization).
${\text{HCN (aq) }} \to {\text{ }}{{\text{H}}^ + } + {\text{C}}{{\text{N}}^ - }$
Therefore, ${\text{N}}{{\text{H}}_4}{\text{OH}}$ solution, NaOH solution, ${\text{C}}{{\text{H}}_3}{\text{COONa}}$ solution, HCN solution all are electrolytes. ${\text{N}}{{\text{H}}_4}{\text{OH}}$ solution and HCN solution are weak electrolytes whereas NaOH solution and ${\text{C}}{{\text{H}}_3}{\text{COONa}}$ solution are strong electrolytes.

Hence, options A, B, C and D are all correct.

Note:
Electrolytes are present in the human body and the balance of the electrolytes in our bodies is essential for the normal functioning of our cells and our organs. Electrolytes found in the body include sodium, potassium, chloride, calcium, magnesium, phosphate and bicarbonate.