A concentration of 10-100 parts per billion (by mass) of Ag+ is an effective disinfectant in swimming pools. However, if the concentration exceeds this range, the Ag+ can cause adverse health effects. One way to maintain an appropriate concentration of Ag+ is to add a slightly soluble salt to the pool. Using Ksp values from Appendix D in the textbook, calculate the equilibrium concentration of Ag+ in parts per billion that would exist in equilibrium with
For this problem, we’re being asked to calculate the equilibrium concentration of Ag+ in parts per billion (ppb) that would exist in equilibrium with AgCl.
Since the AgCl is an ionic compound, it forms ions when dissociating in water. The dissociation of AgCl in water is as follows:
The chloride ion, Cl–, has a charge of –1. Silver then has a charge of +1:
AgCl(s) ⇌ Ag+(aq) + Cl-(aq)
We can construct an ICE table for the dissociation of Ni(OH)2.
Remember that solids are ignored in the ICE table and Ksp expression.