1. HONORS CHEMISTRY
Chapter 3
MATTER

2. CLASSIFICATION OF MATTER

3. Classification of Matter
Matter - anything that has mass and occupies space
anything that has the prop. of intertia
Material - a specific kind of matter
Mixture - matter that contains 2 or more diff. materials
Ex. wood, granite, concrete, air, milk

4. Classification of Matter
Heterogeneous Materials - nonuniform material
has different properties throughout
made of separate phases
Phase - Physically separate part of a material having a uniform set of properties
Interface - boundary betw. phases

5. Classification of Matter
Heterogeneous Mixture - composed of more than one phase
Homogeneous Materials - consist of only 1 phase
same props. throughout
Heterogeneous materials are always mixtures.
Homogeneous mixtures are called solutions.

6. Mixtures Mixtures can vary in composition Solutions consist of:
Solute - dissolved material
Solvent - dissolving material
Same phase - solvent is in greater proportion
Molarity - indicates amt. of solute in a specific amt. of solvent - Concentration

7. Classification of Matter
Substances - homogeneous materials which always have the same composition
Divided into 2 classes
1. Elements - substs. composed of 1 kind of atom
2. Compounds - substs. composed of 2 or more diff. kinds of atoms chemically combined

8. Mixture Vs. Compound MIXTURES not chemically combined
separated by physical means
proportions may vary
COMPOUNDS
chemically combined
separated only by chemical means
proportions can not vary (look up Law of Definite Proportions)

9. Classification of Matter
Organic Substs. - compounds which contain carbon
Inorganic Substs. - elements and compounds of all elements other than carbon

10. PHYSICAL AND CHEMICAL CHANGES

11. Physical Changes
changes in a material in which no new properties appear
Ex. boiling, melting, breaking, etc.

12. Useful Physical Changes
Distillation - means of separating substs. by boiling pt. differences
Fractional Crystallization - means of separating substs. dissolved in the same soln. by using differences in solubilities
Solubility - the amt. of solute that will dissolve in a specific amt. of solvent at a specific temp. (see graph p. 58)

13. Chemical Changes
Changes in which new substs. with new props. are formed.
Ex. burning, digestion, baking, etc.
Separation of a compound requires chemical change

14. Conservation of Mass
During any chemical reaction, the mass of the products is always equal to the mass of the reactants.

15. RULE OF THUMB
If a precipitate, gas, color change, or energy change occurs, a chemical change has probably taken place.

16. Precipitate - a solid subst. that forms from a soln.

17. PHYSICAL AND CHEMICAL PROPERTIES

18. Physical Property
A property that can be observed w/out a change of subst.
A discription of the behavior of a subst. undergoing a physical change
Extensive Properties - Depend on amt. of matter present
Intensive Properties - Do not depend on amt. of matter

19. LOOK UP… Malleability Ductility Tensile Strength (tenacity)
Conductivity

20. Chemical Property
A prop. characteristic of a subst. when it is involved in a chemical change
Defined in terms of interactions w/ other substs.
It is just as important to find out if a subst. does not react as it is to discover if it does react.

21. ENERGY

22. SYSTEM Part of the universe under consideration
Surroundings - everything else
Surroundings do work on the system
System does work on the surroundings

23. HEAT (q) Energy transferred betw. 2 objects bec. of a diff. in temp.
flows from high temp. to low temp.

24. Quantitative measurements of energy changes are expressed in Joules (J).
- derived SI unit
1 J = 1kg*m2/s2
1 calorie = 4.18 J
1 Calorie = 1000 calories = 1 kilocal. = 4180 J

25. Chemical changes are always accompanied by energy change.
Endothermic Reaction - Rxn. in which energy is absorbed
Products have more energy than reactants.
Exothermic Reaction - Rxn. in which energy is given off
Products have less energy than reactants.

26. Rule of thumb for reacting systems
Nature tends to run downhill (exothermic).
Exothermic rxns tend to take place spntaneously (w/out outside help).
Endothermic rxns. usually need external source of energy to take place.

27. Activation Energy - minimum amt. of energy needed to start a rxn.
Calorimeter - device used to meas. energy change in a chem rxn. or physical change

28. Specific Heat (cp)
heat needed to raise the temp. of 1 g of a subst. by 1 Co
In an insulated syst., heat lost by one quantity of matter = heat gained by another.
assume no heat lost to surroundings
energy flows until 2 reach same temp

29. q = mDtcp or q = mcDt Dt = change in temp. (Co)
q = heat lost or gained (J)
m = mass (usually in grams)
cp or c = specific heat (J/g Co)
Dt = change in temp. (Co)