To determine the conductivity of the acidic solutions, we need to consider their pH values. Lower pH values correspond to higher acidity, which typically results in a greater concentration of hydrogen ions (H⁺) in the solution. More H⁺ ions generally mean higher conductivity.
Given the pH values:
- HA (pH 5.6): least acidic
- HC (pH 4.7): moderately acidic
- HB (pH 3.9): most acidic
Based on this, we can analyze the conductivity order:
- HA will have the least conductivity (fewest H⁺ ions).
- HC will have moderate conductivity.
- HB will have the most conductivity (most H⁺ ions).
Therefore, the correct order from least conductive to most conductive is:
HA, HC, HB
So the answer is: HA, HC, HB