Question

Which substances dissolves in pure water and produces a solution that is a good conductor of electricity?

Answer 1

CaCl2 is a good conductor of electricity when dissolved in water.

Answer 2

Answer:

$CaCl_2$

Explanation:

We have to keep in mind that a good conductor would be a substance that has the ability to produce ions (charged species). These species are responsible for the electricity conduction on water.

Therefore, we have to check which ones of these compounds will produce ions in water. For $N_2$ and $O_2$ we have diatomic molecules (also gases) this type of molecules don't have the ability to produce ions due to his simplicity, they already are very stable.

In the sugar molecule $C_6H_12O_6$ we have a covalent compound. The ions are produced by ionic compounds. So, this molecule can be discarded too.

For $CaCl_2$ we have an ionic compound that have the ability to produce ions:

$CaCl_2~~->~~Ca^+^2~+~2Cl^-$

So, this is the compound that would be a good conductor due to the $Ca^+^2$ and the $Cl^-$ ions.