Question

Which of the following is strong electrolyte?
(A)$HCl$
(B)$HBr$
(C)$HI$
(D)All of the above.

Answer 1

Hint: In order to find which hydrogen halide is a strong electrolyte, we must know what a strong electrolyte is. We must know how HCl, HBr and HI dissociate when they are dissolved in water, i.e. whether partially or completely. Knowing these things will help us to know which one is strong electrolyte.

Complete step by step answer:
Before finding which one is a strong electrolyte, let us see what an electrolyte is. Electrolytes are the substance which can conduct electricity. Electrolytes will produce ions when dissolved in water. These ions will be positively and negatively charged. Water is the aqueous solvent in which electrolytes can be dissolved. Non-aqueous solutions where these electrolytes can be dissolved constitute ammonia, acetic acid and ethanol.
Electrolytes are of two types, they are:
- Strong electrolyte.
- weak electrolyte.
Strong electrolytes are the solution which can dissociate \[{H^ + }\]or \[O{H^ - }\] ions completely are called strong electrolytes. Strong electrolytes can be of two types, they are:
- Strong acids.
- Strong bases.
Strong Acids are the solution which can ionize the \[{H^ + }\] ions completely when dissolved in water.
Examples of Strong acids are \[HCl,{H_2}S{O_4},HN{O_3},HBr,HI.\]
Strong bases are the solution which can ionize the \[O{H^ - }\] ions completely when dissolved in water.
Examples of strong bases are \[NaOH,LiOH,KOH,Ca{(OH)_2},Ba{(OH)_2}.\]
As we can see that $HCl$, $HBr$ and $HI$ belongs to strong acids, we can say that all the three are strong electrolytes.

Therefore, the correct answer is option (D) All of the above.

Additional information:
Weak electrolytes are the solution which can only partially dissociate \[{H^ + }\]or \[O{H^ - }\] ions are called weak electrolytes. Weak electrolytes can be of two types, they are:
- Weak acids
- Weak bases
Weak Acids are the solution which get dissociated into \[{H^ + }\] ions partially when dissolved in water.
Examples of weak acids are \[C{H_3}COOH,HF,{H_3}P{O_4}\]
Weak bases are the solution which get dissociated into \[O{H^ - }\] ions partially when dissolved in water.
Examples of weak bases are \[{C_5}{H_5}N,N{H_3}\].

Note: Electrolytes are very important because:
- they can be used to conduct electricity.
- they are used in batteries.
- useful for the chemical reaction to take place.
- important for the functioning of our body.