The more a compound dissociates in water, the better it conducts electricity. Aqueous solutions of three compounds are shown below.

Which of these can be considered a non-electrolyte?

A. X only
Incorrect. Dissociated ions are present.

B. Y only
Correct! No ions are present in this solution.

C. X and Y only
Incorrect. Compound X has ions present in solution.

D. Y and Z only
Incorrect. Compound Z has ions present in solution.

A solid substance was tested in the laboratory. The test results are listed below.

Based on these results, the solid substance could be —

A. Cu
Incorrect. Copper is a solid metal and will not dissociate in solution.

B. CuBr₂
Correct! CuBr₂ is a soluble ionic compound that will dissociate into ions.

C. CaCO₃
Incorrect. CaCO₃ is insoluble and will not dissociate into ions.

D. C₆H₁₂O₆
Incorrect. Glucose is a covalent compound and will not dissociate into ions.

Which of the following is an electrolyte?

A. CH₃OH
Incorrect. Methanol is a covalent compound and will not dissociate.

B. H₂O
Incorrect. Water is a covalent compound and will not dissociate.

C. C₆H₁₂O₆
Incorrect. Glucose is a covalent compound and will not dissociate.

D. KOH
Correct! Potassium hydroxide is an ionic compound and will dissociate into ions in solution.

Which of these salts has the highest conductivity?

A. NaNO₃
Incorrect. NaNO₃ will only dissociate into two ions.

B. MgCO₃
Incorrect. MgCO₃ is insoluble.

C. AgCl₃
Correct! AgCl₃ will dissociate into four ions.

D. CaCl₂
Incorrect. CaCl₂ will only dissociate into three ions.