Question

Which of the following is a bad conductor of electricity?
A. HF
B. HCl
C. HBr
D. HI

Answer 1

Hint: To solve this question, first we need to understand the concept of electricity. As we all know to conduct electricity we need free ions. Conductivity in ionic compounds depends upon the ionization of that compound placed in an aqueous solution. With the help of this, we can find the good and bad conductors of electricity.

Complete step by step answer:
Firstly, let’s understand the concept of conductivity. Conductivity means to conduct electricity which is possible by the presence of free electrons and free ions.
When we consider HF then we know it is a compound with highest stability. As Fluorine is the most electronegative element so it makes the bond of HF stable. Thus, it cannot ionize in an aqueous solution. Therefore, it will not conduct electricity. So, it is a bad conductor of electricity.
Therefore, the option A is correct.
Let’s check the other options too.
We know chlorine is less electronegative than fluorine. So, the bond between H and Cl is weaker. Also, HCl ionizes in an aqueous solution and forms hydronium and chlorine ions. Therefore, it can conduct electricity. Therefore, the option B is incorrect.
Then, we have bromine and iodine both are less electronegative than fluorine and chlorine. So, the bond they form with hydrogen i.e. HBr and HI will be weaker comparatively. Therefore, both HBr and HI will conduct electricity. Therefore, the option C and D is incorrect.

So, the correct answer is Option A.

Note: When we refer to hydrogen halides, the conductivity varies based on the acid strength. As HF is a weak acid it will dissociate in very less water. So, it is a bad conductor of electricity. HCl, HBr, and HI are strong acids that completely dissociate in water to produce ions.