Which of the following compounds in the liquid phase can be considered an electrolyte?
A) CO 2 (carbon dioxide)
B) NaCl (sodium chloride)
C) H 2 O (distilled water)
D) H 2 O 2 (hydrogen peroxide)
3 years ago
Dr. Buzz Dr. Buzz
Best Answer - Chosen by Voters
B, sodium chloride.
I'm guessing your teacher may be referring to aqueous solutions in general.
Carbon dioxide is soluble slightly in water: 0.145 g/100 mL. It is a linear molecule, so does not develop a dipole moment, and does not dissociate. Therefore it is not a good electrolyte.
NaCl is very soluble (about 36 g/100 mL), and dissociates completely; it is an excellent electrolyte.
Distilled water has a slight dissociation (that's where we get pH... H+ concentration = OH- concentration = 10^17 M; however, this is pretty low to be considered a good electrolyte; very weak is being generous;
Hydrogen peroxide is strongly soluble in water, but does not readily dissociate very much. It, too, is a very weak electrolyte.
Ultimately, you can tell how good an electrolyte something is by its conductivity (see reference below).
Let's compare some (the higher the number in (µS/cm), the more conductive):
Hydrogen peroxide: 2
Distilled Water: 0.04
(couldn't find one for CO2)