1) How would you expect the solubility of the following to vary n a series of solutions of increasing ionic strength created by adding KNO3

a) ammonia b) ammonium chloride
2) If the ionic strength was increased by adding KCl, the solubility of which one of the above two solutes be affected significantly and why

To determine how the solubility of ammonia (NH3) and ammonium chloride (NH4Cl) would vary in a series of solutions of increasing ionic strength created by adding KNO3 (potassium nitrate), we need to consider the effect of ionic strength on solubility.

1) For ammonia (NH3):
Ammonia is a weak base that can form ions in an aqueous solution. The solubility of ammonia is affected by the ionic strength of the solution. Increasing the ionic strength of the solution by adding KNO3 will increase the solubility of ammonia.

The reason behind this is that adding KNO3 increases the concentration of ions in the solution, which enhances the electrostatic screening effect. The presence of these additional ions shields the attractive forces between ammonia and water molecules, leading to an increase in the solubility of ammonia.

2) For ammonium chloride (NH4Cl):
Ammonium chloride is a salt that contains both a weak base (NH3) and a strong acid (HCl). The solubility of ammonium chloride is also affected by the ionic strength of the solution. Increasing the ionic strength of the solution by adding KNO3 will decrease the solubility of ammonium chloride.

The reason behind this is the common ion effect. When KNO3 is added, it introduces additional K+ and NO3- ions into the solution. These ions compete with the NH4+ and Cl- ions from ammonium chloride for available water molecules, reducing the solubility of ammonium chloride.

2) If the ionic strength was increased by adding KCl, the solubility of ammonium chloride (NH4Cl) would be affected significantly.

As mentioned earlier, the solubility of ammonium chloride is influenced by the common ion effect. When KCl is added, it introduces additional K+ ions into the solution. Both KCl and NH4Cl contain a common ion (K+), which leads to a decrease in the solubility of ammonium chloride. The increased concentration of K+ ions reduces the availability of water molecules for the NH4+ and Cl- ions, resulting in a decrease in the solubility of ammonium chloride.