Question

A 0.10 M aqueous solution of sodium sulfate, Na2SO4, is a better conductor of electricity than a 0.10 M aqueous solution of sodium chloride, NaCl. Which of the following best explains this observation?
A) NazSO4 is more soluble in water than NaCl is.
B) NazSO4 has a higher molar mass than NaCl has.
C) To prepare a given volume of 0.10 M solution, the mass of NazSO4 needed.
D) More moles of ions are present in a given volume of 0.10 M NazSO4 than in the same volume of 0.10 M NaCl.
E) The degree of dissociation of NazSO4 in solution is significantly greater than that of NaCl.

Answer 1

Answer: D) More moles of ions are present in a given volume of 0.10 M $Na_2SO_4$ than in the same volume of 0.10 M NaCl.

Explanation:

A electrolyte is a solution that dissociates completely when dissolved in water. The ions act as good conductors of electric current in the solution.

More is the number of ions , more will be the conductance and hence the solution will be a better conductor of electricity.

0.10 M aqueous solution of $Na_2SO_4$ is a better conductor of electricity as it dissociates to give three ions whereas 0.10 M aqueous solution of $NaCl$ dissociates to give two ions only.

$Na_2SO_4\rightarrow 2Na^++SO_4^{2-}$

$NaCl\rightarrow Na^++Cl^{-}$

Thus 0.10 M aqueous solution of sodium sulfate, $Na_2SO_4$ , is a better conductor of electricity as more moles of ions are present in a given volume of 0.10 M $Na_2SO_4$ than in the same volume of 0.10 M $NaCl$