solubility and temperature/ explore learning
Which of the charts below is most likely to represent a saturated solution?
- Chart C Explanation: Because there is solute at the bottom of the container, we can assume the solution cannot hold any more solute. In other words, it is saturated.
Which one of the following graphs best describes the solubility of potassium nitrate (KNO3)in water at different temperatures?
- Graph C Explanation: Your data from this simulation should have given you a graph that resembles Graph C. The other graphs do not match the data. Graph A shows a line that increases linearly. Graph B shows a line that decreases. Graph D does not increase or decrease. It would be correct only if temperature had no effect on the solubility of potassium nitrate in water.
Imagine you have two beakers. Both beakers are filled with the same amount of water. The water in both beakers is the same temperature as well. You add 50 g of Substance A to the first beaker, and 50 g of Substance B to the second beaker. After stirring both beakers, there is a small pile of Substance A at the bottom of the first beaker. None of Substance B is visible in the second beaker. Which of the following statements is true?
- Substance A is less soluble in water than Substance B. Explanation: Substance A is less soluble in water than Substance B. Solubility tells you how easily one substance can dissolve in another. From the question, you know that at least 50 g of Substance B can be dissolved in a beaker of water. However, the same amount of water becomes saturated when 50 g of Substance A is added. Therefore, Substance A is less soluble in water than Substance B.
You begin pouring sodium chloride into a glass of water. For a long time, the sodium chloride just dissolves in the water, but suddenly it begins to pile up at the bottom of the glass. Which statement is true?
- The water is saturated Explanation: When water becomes saturated it means that you can no longer dissolve a particular substance in the water. Since the sodium chloride was no longer dissolving in the water, you know that the water had become saturated.
Comparing potassium nitrate (KNO3) and sodium chloride (NaCl), which chemical's solubility (in water) is most affected by change in temperature?
- potassium nitrate Explanation: The amount of potassium nitrate that can dissolve in water increases by more than 10 times between 5 degrees and 95 degrees. The amount of sodium chloride that can dissolve changes by a factor of less than two.
