100g of water are saturated with KNO3 at 50Ëšc. how many grams of KNO3 will crystallize out if the temperature cools to 40Ëšc?

A. 10g
B.19g
C.64g
D.83g

I need to know the solubility of KNO3 at 50 C and 40 C. You must have a table or a graph that gives you this information.

To determine the amount of KNO3 that will crystallize out when the temperature cools, we need to calculate the difference in solubility of KNO3 at 50°C and 40°C.

First, we need to find the solubility of KNO3 at each temperature. The solubility of KNO3 in water increases with temperature. Let's assume that at 50°C, 100g of water can dissolve X grams of KNO3.

Next, we need to find the solubility of KNO3 at 40°C. Again, let's assume that 100g of water can dissolve Y grams of KNO3 at this temperature.

Since the question states that water is saturated with KNO3 at 50°C, it means that X grams of KNO3 are dissolved in 100g of water at that temperature. Therefore, X represents the solubility of KNO3 at 50°C.

Now, we need to find the solubility of KNO3 at 40°C. We can use the known solubility relationship: the solubility of a substance generally decreases as temperature decreases. So, the solubility of KNO3 at 40°C will be less than X. Let's assume the solubility at this temperature is Y grams.

To find the amount of KNO3 that will crystallize out, we subtract the solubility at 40°C (Y) from the solubility at 50°C (X). Therefore, the amount of KNO3 that will crystallize out is X - Y grams.

Unfortunately, we do not have the specific values for X and Y in this question. Therefore, we cannot directly determine the amount of KNO3 that will crystallize out. Without this information, we cannot select any of the given answer options (A, B, C, or D) as the correct answer.