Are salts containing potassium, sodium, and lithium soluble in water according to the material?

• A. Insoluble
• B. Soluble
• C. Depends on the counter-ion
• D. Reacts with water

Answer: (B)

Solubility in water hinges on how easily the solid lattice can be broken apart and how strongly the resulting ions are stabilized by water. For salts of potassium, sodium, and lithium, the ions carry a +1 or -1 charge and are relatively small in charge density, so the lattice energy of the solid isn’t very high. Water is highly polar and surrounds each ion with a hydration shell, releasing energy as it does so. This hydration energy offsets the energy required to break the solid’s lattice, making dissolution favorable. As a result, these salts dissolve readily in water to give aqueous ions like K+, Na+, or Li+ along with their respective counter-ions.

So, these salts are soluble in water according to the material. The other ideas don’t fit because these salts don’t typically react with water to form new substances in normal conditions, and the general behavior is solubility rather than insolubility or dependence on a specific counter-ion.