All of the following are TRUE for activities and activity coefficients, except: A) activity for a chemical species is the product of concentration and activity coefficient. B) the activity coefficient corrects for non-ideal behavior due to ionic strength. C) as ionic strength increases, the value of the activity coefficient increases. D) for ions, the activity coefficient approaches unity as the ionic strength approaches 0. E) the activity coefficient for neutral molecules is approximately unity.

C) as ionic strength increases, the value of the activity coefficient increases.

Explanation:

The effective concentration of ions available for reactions is known as the activity of the ion.

The activity coefficient important in chemistry because it accounts for the deviation of a solution from ideal behaviour.

The activity of a chemical species is defines as the product of concentration and activity coefficient.

Following the Debye–Hückel limiting law; log γ = −0.509z2I1/2. The ionic strength of a solution tends to increase as the activity coefficient (γ) of the ion decreases.