Chapter 4
Properties of Matter
- Properties of substances.
- Physical properties - taste, color, state, density, luster, hardness, melting point... Can you name others?
- Chemical properties - The ability or capacity to form other, new substances by reaction or decomposition.
- Physical changes.
- Compounds don't break down (atom arrangement does not change. (e.g., change of state, particle size, mixing).
- Chemical changes.
- Change in chemical composition. Compounds break down or are formed. Atoms are rearranged, but elements do not change. (e.g., burning, cooking, breathing, photosynthesis, fermentation).
- Conservation of Mass.
- Mass of reactants equals mass of products.
- Energy.
- Capacity of matter to do work.
- Potential energy: stored energy.
- Kinetic energy: energy of motion.
- Chemical energy = Heat, energy stored in compounds; released or absorbed during chemical reactions.
- Quantitative Measurement of Heat.
- 1 calorie = 4.184 Joules
- Know the difference between heat and temperature.
- Specific Heat = Quantity of heat required to raise
the temperature of one gram of a substance by 1 degree Celsius.
- Mass times specific heat times change in temperature
equals the amount of heat gained or lost.
- mC(T2-T1) = Heat
where m=mass in grams, C=specific heat,
T=temperature in Celsius, and Heat is in Joules.
- If you know the specific heat of a group of substances, you should be able to tell which will require the least (or most) heat to produce a certain change of temperature.
- Given the mass and specific heat of a substance, you can predict the change in temperature if a certain amount of heat is lost or gained.
- Know how to calculate the final temperature if a piece of hot metal is dropped into water, or if two liquids of different temperatures are mixed.
- What are the units for specific heat?
Return to the
CHEM 151 Syllabus.
Return to the Schedule.
Go back to the study guide for
Chapter 3 or
Chapter 5.
Return to the
Chem 151 main home page.
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