Video Transcript
The diagram below shows four beakers, each containing 100 milliliters of water at different temperatures. Potassium chloride was added into each beaker until the solution became saturated. Which of the solutions is at the highest temperature?
Each of the four solutions is a saturated solution. A saturated solution is a solution that contains the maximum amount of solute dissolved in a solvent at a given temperature. Since all four solutions have the same type of solute, potassium chloride, and the same type and amount of solvent, which is 100 milliliters of water, we must consider why each beaker can create a saturated solution with different amounts of potassium chloride. The beakers differ by their temperature. So the factor affecting the amount of solute that can be dissolved is the temperature.
In general, for more solid solute to be dissolved in the same amount of solvent, the temperature can be increased. We can use this information to analyze the four beakers and arrange them from the least amount of solute, and thus the solution at the lowest temperature, to the most amount of solute, and thus the solution with the highest temperature.
Solution C has the least amount of solute dissolved in the 100 milliliters of water, with only 27.6 grams of potassium chloride. So we can assume that solution C is at the lowest temperature. Solution B would be next, with 34.0 grams of potassium chloride. And solution A would be warmer, with 42.6 grams of potassium chloride dissolved. Solution D would be at the highest temperature, since this solution has the highest amount of solute dissolved at 57.6 grams. Therefore, the saturated solution that is at the highest temperature is solution D.
