Which of the following statements is not true?

The pH of solutions is temperature dependent.
Strong acids exhibit large equilibrium constants.
A weak acid is not completely dissociated.
The pH of a strong base approaches 7 as base concentration decreases.
When CO2 is absorbed by pure water, the solution conductivity decreases.

Question

Which of the following statements is not true?

The pH of solutions is temperature dependent.
Strong acids exhibit large equilibrium constants.
A weak acid is not completely dissociated.
The pH of a strong base approaches 7 as base concentration decreases.
When CO2 is absorbed by pure water, the solution conductivity decreases.

anonymous · Answer

The last one.  When CO2 is absorbed by water, it forms a mixture of carbonic acid (H2CO3), bicarbonate anion (HCO3-), carbonate anion (CO3-2), and hydrogen cation (H+ or H3O+, depending on how you want to write it).

The addition of all these ionic species increases the conductivity of the water, because electric current can flow by means of these ions moving.