what mass of precipitate will form if a saturated solution of potassium nitrate is dropped from a temperature of 70 degrees celsius to a temperature of 45 degrees celsius?
Do you have anything (a graph, table, etc) that tells you (or allows you to obtain) the solubility of KNO3 at 70 C and 45 C?
Test Tube # Gram of KNO3 + ml of H2O Crystallization temp. (oC)
1 6.00g/10ml 50 oC
2 9.00g/10ml 54 oC
3 12.00g/10ml 65 oC
4 15.00g/10ml 72 oC
that is the data i have, and i put it into a graph
To determine the mass of precipitate that will form, we need to consider the solubility of potassium nitrate at different temperatures. As the temperature decreases, the solubility of most solid solutes decreases as well, leading to the formation of a precipitate.
To find the mass of the precipitate formed, we need to know the solubility of potassium nitrate at both temperatures. Let's assume the initial saturated solution at 70 degrees Celsius contains 100 grams of potassium nitrate.
1. Find the solubility of potassium nitrate at 70 degrees Celsius: You can search for a solubility table or use a reliable source to find the solubility of potassium nitrate at 70 degrees Celsius. Let's say the solubility is 150 grams per 100 grams of water.
2. Determine the amount of excess potassium nitrate in the initial solution: Since the solution is saturated, we can assume that there is no excess potassium nitrate remaining in the solution as it is in equilibrium with the solid precipitate.
3. Find the solubility of potassium nitrate at 45 degrees Celsius: Again, refer to a solubility table or a reliable source to find the solubility of potassium nitrate at 45 degrees Celsius. Let's say the solubility is 75 grams per 100 grams of water.
4. Calculate the amount of dissolved potassium nitrate at 45 degrees Celsius: Since the solution was initially saturated at 70 degrees Celsius, the remaining dissolved potassium nitrate at 45 degrees Celsius should be equal to the saturation point at this temperature. In our example, this would be 75 grams.
5. Determine the mass of precipitate formed: The difference between the initial amount of potassium nitrate (100 grams) and the remaining dissolved amount at the lower temperature (75 grams) gives us the mass of the precipitate formed. In this case, the mass of the precipitate would be 100 grams - 75 grams = 25 grams.
Therefore, if a saturated solution of potassium nitrate is dropped from 70 degrees Celsius to 45 degrees Celsius, approximately 25 grams of precipitate will form.