7. how many grams of potassium chloride can be dissolved in 200 g of water at 80 °c?\n8. at 40 °c, how much…

7. how many grams of potassium chloride can be dissolved in 200 g of water at 80 °c?\n8. at 40 °c, how much potassium nitrate will be dissolved in 300 g of water?\n9. which salt shows the least change in solubility from 0°c to 100 °c?\n10. which substance shows a decrease in solubility from 0°c to 100 °c?\n11. at 30°c, 90 g of sodium nitrate is dissolved in 100 g of water. is this solution saturated, supersaturated, or unsaturated?

7. how many grams of potassium chloride can be dissolved in 200 g of water at 80 °c?\n8. at 40 °c, how much potassium nitrate will be dissolved in 300 g of water?\n9. which salt shows the least change in solubility from 0°c to 100 °c?\n10. which substance shows a decrease in solubility from 0°c to 100 °c?\n11. at 30°c, 90 g of sodium nitrate is dissolved in 100 g of water. is this solution saturated, supersaturated, or unsaturated?

Answer

Explanation:

Step1: Locate solubility of KCl at 80°C

From the solubility - temperature graph, the solubility of potassium chloride (KCl) at 80°C is 51 g per 100 g of water.

Step2: Calculate amount for 200 g of water

Since the solubility is 51 g per 100 g of water, for 200 g of water, the amount of KCl that can be dissolved is $51\times2 = 102$ g.

Step3: Locate solubility of $KNO_3$ at 40°C

From the graph, the solubility of potassium nitrate ($KNO_3$) at 40°C is 64 g per 100 g of water.

Step4: Calculate amount for 300 g of water

For 300 g of water, the amount of $KNO_3$ that can be dissolved is $64\times3=192$ g.

Step5: Analyze solubility - change for different salts

By observing the graph for different salts from 0°C to 100°C, we find that sodium chloride (NaCl) shows the least change in solubility.

Step6: Identify substance with decreasing solubility

By observing the graph, we see that cerium(III) sulfate ($Ce_2(SO_4)_3$) shows a decrease in solubility from 0°C to 100°C.

Step7: Locate solubility of $NaNO_3$ at 30°C

From the graph, the solubility of sodium nitrate ($NaNO_3$) at 30°C is 96 g per 100 g of water.

Step8: Determine solution type

Since 90 g of $NaNO_3$ is dissolved in 100 g of water and the solubility at 30°C is 96 g per 100 g of water, the solution is unsaturated.

Answer:

  1. 102 g
  2. 192 g
  3. Sodium chloride (NaCl)
  4. Cerium(III) sulfate ($Ce_2(SO_4)_3$)
  5. Unsaturated