What will happen to 42 g of KCl solution per 100 g of water when cooled from 60 degrees Celsius to 0 degrees Celsius?
I don't know the solubility (but you can look it up); however, I think it more than likely that some of the KCl will crystallize.
To determine what will happen to the KCl solution when cooled, we need to consider the solubility of KCl in water as a function of temperature.
Solubility is defined as the maximum amount of solute that can dissolve in a given amount of solvent at a certain temperature. In the case of KCl in water, the solubility generally increases with increasing temperature.
To find the solubility of KCl in water at different temperatures, you can refer to a solubility table or use a solubility chart available online or in chemistry textbooks.
Let's assume, for the sake of explanation, that the solubility of KCl in water at 60 degrees Celsius is 40g/100g of water and at 0 degrees Celsius is 30g/100g of water.
You mentioned having 42g of KCl solution per 100g of water. Since the solubility at 60 degrees Celsius is 40g/100g of water, the solution is saturated (maximum amount of KCl is dissolved) at this temperature. Therefore, if you cool the solution from 60 degrees Celsius to 0 degrees Celsius, some of the KCl will start to precipitate out of the solution because the solubility of KCl decreases as the temperature decreases.
Since the solution contains 42g/100g of KCl and the solubility at 0 degrees Celsius is 30g/100g of water, 12g of KCl will exceed the solubility limit and crystallize as solid KCl. The precipitated KCl will form crystals or sediment at the bottom of the container as the temperature drops.
It's important to note that the exact solubility values may vary depending on the specific conditions, so referring to a solubility chart or conducting experiments would provide more accurate results.