Question

A conductivity experiment is set up with a light bulb and five beakers of \[0.1{\text{ }}M\;\]solutions of the substances below. Which solution would allow the bulb to glow the brightest?
A) \[{C_6}{H_{12}}{O_6}\]
B) \[HCl\]
C) \[Si{O_2}\]
D) \[H{C_2}{H_3}{O_2}\]
E) \[C{H_3}OH\]

Answer 1

Hint:Conductivity is a measurement of the ability of an aqueous solution to transfer an electrical current. The current is carried by ions, and therefore the conductivity increases with the concentration of ions present in solution.
When strong acids react with water they are completely converted to ions. Therefore their solutions have high electrical conductivity and the light bulb is lit up very brightly.

Complete answer:
The experiment will test the conductivity of various solutions with a light bulb apparatus, If the circuit is completed by a solution containing a large number of ions, the light bulb will glow brightly indicating a strong ability to conduct electricity

As per Conductivity Principle an acid or base which strongly conducts electricity contains a large number of ions and is called a strong acid or base. An acid or base which conducts electricity only weakly contains only a few ions and is called a weak acid or base.
As per given options \[HCl\] – is a strong acid. Every \[HCl\] molecule splits into a \[{H^ + }\;ion\] and a \[C{l^ - }\;ion\] in the reaction. Strong acids have mostly ions in solution, therefore the bonds holding \[H\] and \[Cl\] together must be weak. Strong acids easily break apart into ions.
Now, when HCl is in the solution of water, it forms ions. We can write the chemical equation as:
\[HC{l_{\left( {aq} \right){\text{ }}}} \to {\text{ }}{H^ + }\; + {\text{ }}C{l^ - }\]
Ionic solutions have the capability to conduct electricity. HCl solution would allow the bulb to glow the brightest. HCl is a strong acid and completely dissociates in aqueous solution. Hence, it gives the maximum number of current carrying ions.

So the option (B) is correct.

Note:
 In \[{C_6}{H_{12}}{O_6}\] glucose (sugar) readily dissolves in water, but because it does not dissociate into ions in solution, it is considered a non-electrolyte; solutions containing glucose do not, therefore, conduct electricity.