| A | B |
|---|
| Difference in Temperature equation | Delta T = Tf - Ts |
| Find Heat lost or gained equation | Heat(cal) = Mass (g) x Delta T (oC) x sp ht (cal/g oC) |
| specific heat (sp ht) | number of calories of heat needed to change the temp. of 1 gram of the substance 1o Celcius (oC) |
| sp ht of water | 1 cal/g/oC |
| Amount of heat needed to raise the temp. of water depends on | 1) mass 2) amount of change in its temp. |
| Loss of 30 oC | -30 oC |
| Temperature | measures the average kinetic energy of the particles/atoms (their movement) |
| Heat | energy that can be transferred between matter as a result of differences in temp. |
| Heat moves in predictable ways. It flows from | warmer objects to cooler ones, until both reach the same temp. |
| Conduction, Convection and Radiation | Types of heat transfer |
| Absolute zero | minimum amount of activity (zero activity) a substance can have. It has never been reached |
| Absolute zero is measured on the | Kelvin scale |
| Most substances expand when heated and contract when cooled with the exception of | water. Water expands when cooled from liquid to solid. Contracts when changes from solid to liquid. |
| The ability of a substance to prevent heat LOSS or GAIN. | Insulate |
| The higher the specific heat of a substance, | the better the substance is as an insulator. |
| conduction | heat is transferred by collision of molecules-particles must be in CONTACT. Ex. hand touches bottom of hot teapot. |
| radiation | heat is transferred through waves. Ex. Sun, warmth from a fireplace |
| convection | heat is transferred through moving currents of liquid or gas-the individual molecules move Ex. hot air rising to the top of the room. |
| How many calories are lost when 25 ml of water cools from 65 oC to 55 oC ? | - 250 cal |
| water boiling oC | 100 oC |
| water freezing oC | 0 oC |
| when a substance changes states heat is | either lost or gained. |
| Where does the heat energy from your cooling hot chocolate go? | into the air around the mug itself. |
| If a substance starts at 90 oC and ends at 75 oC , what is the temperature change? | 15 oC are lost; or -15 oC |
| Chemical Change | a change in which the composition of a substance changes. The substance changes into something else. |
| Physical Change | change in which the form or appearance of matter changes, but not its composition (what it is made of) |
