A saturated solution of kno3 at 70°c is cooled to 10°c. What mass of a solid of precipitate out of solution.

I need to know the solubility of KNO3 at 70 C and at 10 C.

60g

To find the mass of the precipitate, we need to calculate the difference in solubility of KNO3 between 70°C and 10°C.

Step 1: Determine the solubility of KNO3 at 70°C:
The solubility of KNO3 at 70°C is 127 g/100 mL.

Step 2: Determine the solubility of KNO3 at 10°C:
The solubility of KNO3 at 10°C is 26.7 g/100 mL.

Step 3: Calculate the difference in solubility:
The difference in solubility is 127 g/100 mL - 26.7 g/100 mL = 100.3 g/100 mL.

Step 4: Convert the difference in solubility to grams per mL:
Since 100.3 g/100 mL of KNO3 will precipitate out for every 100 mL of solution, we can say that 1 g/mL of KNO3 will precipitate out.

Step 5: Determine the volume of the saturated solution:
We need to know the volume of the saturated solution to calculate the mass of precipitate. Let's assume we have 200 mL of the saturated solution.

Step 6: Calculate the mass of the precipitate:
Multiply the volume of the saturated solution by the precipitate rate:
200 mL x 1 g/mL = 200 g.

Therefore, if 200 mL of the saturated KNO3 solution at 70°C is cooled to 10°C, a mass of 200 g of the KNO3 precipitate will form.

To find the mass of the solid precipitated out of the solution, we need to determine the solubility of KNO3 at both 70°C and 10°C.

The solubility of a substance generally increases with temperature, which means that more solute can dissolve in a given amount of solvent as the temperature rises.

To find the solubility of KNO3 at 70°C, you can search for a solubility table or use a reference book. Let's say we find that the solubility of KNO3 at 70°C is 120 grams per 100 grams of water.

Next, we need to determine the saturated solution's concentration at 70°C. This would be equal to the solubility of KNO3 at 70°C, which is 120 grams per 100 grams of water.

Now, we need to find out how much KNO3 remains dissolved when the solution is cooled to 10°C. At 10°C, the solubility of KNO3 is different. Let's say we find that the solubility at 10°C is 50 grams per 100 grams of water.

The difference between the initial concentration at 70°C and the solubility at 10°C represents the amount of KNO3 that will precipitate out.

Using the given information, the amount of KNO3 that precipitates out can be calculated as follows:

Amount of KNO3 precipitated out = Initial concentration - Final concentration
= 120 g/100 g - 50 g/100 g
= 70 g/100 g

Finally, to determine the mass of the solid precipitate, we need to know the total amount of solution. Let's say we have 200 grams of the saturated solution.

Mass of solid precipitate = Amount of KNO3 precipitated out × Total mass of solution
= (70 g/100 g) × 200 g
= 140 grams

Therefore, 140 grams of solid KNO3 will precipitate out of the solution when it is cooled from 70°C to 10°C.