A KCl solution containing 42g of KCl per 100.0 g of water is cooled from 60 C to 0 C . What will happen during cooling?
the water will freeze
A certain portion of the KCl will precipitate out of the solution.
During cooling, the KCl solution will undergo a process called cooling or cooling down, which results in a decrease in temperature. As the solution cools from 60°C to 0°C, several changes will occur.
1. Initially, at 60°C, the KCl particles in the solution have more energy and are moving rapidly, causing the solution to be in a dissolved state. The water molecules provide a medium for the KCl to dissolve, forming a homogeneous mixture.
2. As the solution begins to cool, the energy of the KCl particles decreases, causing their movement to slow down. This reduction in energy reduces the solubility of KCl in water.
3. At a certain temperature, called the solubility limit, the cooling solution will reach a point where it can no longer dissolve all the KCl. This is because the cooler temperature reduces the ability of water molecules to surround and separate the KCl ions. As a result, any excess KCl will start to separate from the solution as solid particles.
4. The separated solid KCl particles may form crystals and will settle at the bottom of the container due to gravity. This is known as precipitation, where the solute (KCl) is no longer completely soluble in the solvent (water) at the given temperature.
Therefore, during the cooling process, the KCl solution will eventually reach a temperature where KCl will begin to separate from the solution and form crystals or precipitate.