Question

Equimolar solutions of copper(II) chloride, aluminum chloride, lithium chloride and calcium chloride are prepared. Which solution would be expected to have the highest conductivity? Hint: write the chemical formulas.

Answer 1

Answer: The aluminium chloride solution will have the highest conductivity.

Explanation:

Conductivity is defined as the ability of a substance to conduct electricity.

When an ionic compound is dissolved in water, it dissociates into its respective ions.

As electricity is the flow of ions or electrons. So, an ionic compound will conduct electricity due to the presence of ions in the solution.

More number of ions dissociated in the solution, more amount of electricity will be conducted.

For the given options:

1) Copper (II) chloride

The chemical formula of the given compound is $CuCl_2$

It will dissociate to form 1 mole of $Cu^{2+}$ ions and 2 moles of $Cl^-$ ions

Total number of ions in the solution = 3

2) Aluminium chloride

The chemical formula of the given compound is $AlCl_3$

It will dissociate to form 1 mole of $Al^{3+}$ ions and 3 moles of $Cl^-$ ions

Total number of ions in the solution = 4

3) Lithium chloride

The chemical formula of the given compound is LiCl

It will dissociate to form 1 mole of $Li^{+}$ ions and 1 mole of $Cl^-$ ions

Total number of ions in the solution = 2

4) Calcium chloride

The chemical formula of the given compound is $CaCl_2$

It will dissociate to form 1 mole of $Ca^{2+}$ ions and 2 moles of $Cl^-$ ions

Total number of ions in the solution = 3

As, the number of ions is highest for aluminium chloride. So, it will have the highest conductivity.

Hence, the aluminium chloride solution will have the highest conductivity.