To determine the order of conductivity of the acidic solutions based on their pH values, we need to consider that lower pH values indicate higher hydrogen ion concentration, which typically leads to higher conductivity.
Given the pH values:
- HA: 5.6 (least acidic)
- HC: 4.7
- HB: 3.9 (most acidic)
We can rank them in terms of conductivity from least to most:
- HA (least conductive, highest pH)
- HC
- HB (most conductive, lowest pH)
Thus, the correct order from least conductive to most conductive is:
HA, HC, HB
So the correct response is: HA, HC, HB