Lesson 3 — Activity 3: The Effect of Temperature on Solubility
Lesson 3 — Activity 3: The Effect of Temperature on Solubility
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In L1 — A1, you learned about the particle theory of matter. You may recall that one of the main points of this theory is that particles speed up with heat and slow down with cold. In this activity, you will investigate the effects of temperature change on solubility and explain this effect based on the particle theory.
As you may expect, when talking about the solubility of a solid added to a liquid, temperature has a direct effect on solubility. As the temperature increases, the particles of the solid move faster, which increases the chances that they will interact with more of the solvent particles. This results in increasing the rate at which a solution occurs.
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In some cases, temperature can also increase the amount of solute that can be dissolved in a solvent. As the temperature is increased, more solute particles will be dissolved. For example, when you add sugar to water, a solution is quite easily made. When you heat that solution and keep adding sugar, you will find that large amounts of sugar can be added as the temperature keeps rising. There are other examples, though, where increasing the temperature has very little effect on how much solute can be dissolved. Table salt is a good example: You can dissolve just about the same amount of table salt in ice water as you can in boiling water.
For all gases, as the temperature increases, the solubility decreases. A theory called the kinetic molecular theory can be used to explain this phenomenon. As the temperature increases, the gas molecules move faster and are then able to escape from the liquid. The solubility of the gas, then, decreases.
Self-Check
Try This!
Try the questions below on your own first and then click on the tab to check your answers!
Decide if the following statements are true or false.
1. One of the main points of the particle theory is that particles speed up with heat and slow down with cold.
2. When talking about the solubility of a solid added to a liquid, temperature has no effect on solubility.
3. For all gases, as the temperature increases, the solubility increases.
4. Adding heat affects the solubility of solids and liquids.
1. True
2. False. Temperature has a direct effect on solubility.
3. False. For all gases, as the temperature increases, the solubility decreases.
4. True
Digging Deeper
Have
you ever helped someone in your family can fruit? Every fall, many
people put peaches, nectarines, apricots, plums, or pears into cans or
jars so they can enjoy fruit throughout the winter months.
Along with the fruit, many people prepare a syrup to mix with the fruit to add sweetness to the product. To make syrups for canning, sugar and water are combined in a pot and heated until the sugar dissolves.
You will see how sugar dissolves in water that is heated in the next assignment.
