What is a material's heat capacity?
You’ve seen that the rate at which heat is transferred from one place to another depends on the difference in temperature. You've also explored how the rate of heat transfer is affected by properties of materials; energy can be transferred by convection in a liquid or gas, but not in a solid; a silver spoon conducts heat more easily than a wooden spoon.
But when the same amount of energy is transferred to the same amount of two different materials, they won't necessarily change temperature at the same rate. You may have noticed that it takes a really long time to heat up mashed potatoes, or that a few minutes after the pizza comes out of the oven, the pizza sauce still burns your mouth but the crust doesn't.
Physicists explain these phenomena in terms of specific heat capacity: the amount of heat necessary to change the temperature of a substance.
The substance that you focus on this week is water. 71% of the surface of our "blue planet" is covered with water; we use it everyday. Investigating the properties of water will help us to understand everyday domestic phenomena and it will give us clues about larger global phenomena involving temperature change.
This Week's Plan
The question this week is: when equal amounts of heat are transferred to or from different materials, how does the temperature change? You will compare water to other materials. You'll investigate temperature change while energy is transferred to and from those materials, and you'll consider how energy is stored in them.
Blue Marble: Next Generation
NASA’s Earth Observatory
- Understand how heat transfer differs from heat capacity
What you need
- Mass balance
- 2 400 ml glass beakers
- 100 grams of water, at room temperature
- 100 grams of another material of your choice (e.g., sand, oil, soup) at room temperature
- A means to heat 100 gram samples (e.g., hot water bath, microwave oven, lab burner)
From your kit
- Temperature probes
- 100 grams of sand (optional)