Question

Bad conductor of electricity is:
A. ${{\text{H}}_{\text{2}}}{{\text{F}}_{\text{2}}}$
B. ${\text{HCl}}$
C. ${\text{HBr}}$
D. ${\text{HI}}$

Answer 1

Hint: To conduct electricity free ions are required. The conductivity of the ionic compound depends upon the ionization of that compound in aqueous solution

Step by step answer: Conductivity is the ability to conduct electricity which depends upon the presence of free electrons as well as free ions.
Free ions produced when ionic compounds dissociation in water.

The ${{\text{H}}_{\text{2}}}{{\text{F}}_{\text{2}}}$ compound has high stability. The fluorine is the most electronegative element so, the hydrogen-fluorine bond is a very stable and thus the ${{\text{H}}_{\text{2}}}{{\text{F}}_{\text{2}}}$ does not ionize in aqueous solution.
${{\text{H}}_{\text{2}}}{{\text{F}}_{\text{2}}}$does not conduct electricity so, ${{\text{H}}_{\text{2}}}{{\text{F}}_{\text{2}}}$ is a bad conductor of electricity and
Thus option (A) is correct.

The chlorine atom has less electronegative than fluorine so the hydrogen-chlorine bond is weak comparatively. ${\text{HCl}}$ ionizes in the aqueous solution forming hydronium and chloride ions and so, ${\text{HCl}}$ conducts electricity. So, option (B) is incorrect.
The bromine atom has less electronegative than fluorine and chlorine so the hydrogen-bromine bond is weak comparatively. ${\text{HBr}}$ ionizes in the aqueous solution forming hydronium and bromide ion and so, ${\text{HBr}}$ conducts electricity. So, option (C) is incorrect.

The iodine atom has less electronegative than fluorine, chlorine and bromine so the hydrogen-iodine bond is weak comparatively. ${\text{HI}}$ ionize in the aqueous solution forming hydronium and iodide ion and so, ${\text{HI}}$ conduct electricity. So, option (D) is incorrect.

Therefore, option (A) ${{\text{H}}_{\text{2}}}{{\text{F}}_{\text{2}}}$ is correct.

Note: For the hydrogen halides, the conductivity can be decided on the basis of acidic strength. The ${\text{HF}}$ is weak acid it dissociates very less in water and thus a bad conductor whereas the hydrogen chloride, hydrogen bromide and hydrogen iodide are strong acids, they dissociate completely in water thus produce ions and conduct electricity.