CHEMICAL REACTIONS CHAPTER 5

THE NATURE OF CHEMICAL REACTIONS CHAPTER 5.1

Words to describe chemical reactions. __________

SIGNS OF A CHEMICAL REACTION 1.A ______ (bubbles) may be given off. 2.A ______ may settle out of solution. 3. _______ may be released as light or heat. 4. _______ may change. 5. A new ________ may form.

CHEMICAL REACTIONS CAUSE CHANGE Chemical reactions rearrange atoms which changes the substances. REACTANT – ___________________ PRODUCT – ____________________

ENERGY AND REACTIONS 1. ENERGY MUST BE ADDED BEFORE A CHEMICAL REACTION WILL BEGIN. 2. ENERGY WILL BE RELEASED AS THE REACTION TAKES PLACE. 3.SOME FORMS and EXAMPLES OF ENERGY ARE: 1.HEAT - _________________________ 2.ELECTRICITY - _________________ 3.SOUND - _______________________ 4.LIGHT - ________________________ 4.SOME REACTIONS ARE: 1.EXOTHERMIC – ENERGY IS ____________ (FEELS WARM). 2.ENDOTHERMIC – ENERGY IS ____________ (FEELS COLD)

REACTION TYPES CHAPTER 5.2

CLASSIFYING REACTIONS 1 SYNTHESIS AT LEAST _____ REACTANTS JOIN TO FORM A NEW PRODUCT. example: 2Na + Cl 2 2NaCl 2H 2 + O 2 2H 2 O

2 DECOMPOSITION A REACTION IN WHICH SUBSTANCES ARE BROKEN APART. example: 2H 2 O 2H 2 + O 2 2NaHCO 3 Na 2 CO 3 + ___ + CO 2 H2OH2O

3 COMBUSTION (BURNING) REACTIONS THAT USE OXYGEN AS ONE REACTANT. example: 2CH 4 + 4O 2 2CO 2 + 4H 2 0 (Study page 156 in the text)

4 SINGLE DISPLACEMENT ATOMS OF ONE ELEMENT TAKE THE PLACE OF ANOTHER ELEMENT IN A COMPOUND. example: 3CuCl 2 + 2Al 2AlCl 3 +3Cu Zn + 2HCl_______ + H 2 ZnCl 2

5 DOUBLE DISPLACEMENT TWO COMPOUNDS APPEAR TO CHANGE IONS. example: FeS + 2HCl FeCl 2 + H 2 S CaC 2 + H 2 OC 2 H 2 +_____ CaO

BALANCING CHEMICAL REACTIONS CHAPTER 5.3

BALANCING RULES REACTANTS Y _ _ _ _ PRODUCTS # of REACTANTS E _ _ _ _ _ _ # of PRODUCTS NUMBER OF ATOMS ON EACH SIDE OF THE EQUATION MUST BE EQUAL (CONSERVATION - MATTER CANNOT BE CREATED OR DESTROYED) SUBSCRIPTS CANNOT BE CHANGED ONLY COEFFICIENTS CAN BE CHANGED

BALANCING EXAMPLE UNBALANCED F 2 + NaCl NaF + Cl 2 2F1F1Na 1Cl2Cl BALANCED F 2 +2NaCl 2NaF + Cl 22F2Na2Cl

RATES OF CHANGE CHAPTER 5.4

SIX FACTORS AFFECTING REACTION RATES FOR REACTIONS TO OCCUR THE PARTICLES OF THE REACTANTS MUST _ _ _ _ _ _ WITH ONE ANOTHER. GOD ALLOWS US TO CONTROL THE RATE OF THEIR COLLISIONS.

1. TEMPERATURE HIGHER TEMPERATURE INCREASES THE RATE: Examples: - - -

2. SURFACE AREA LARGER SURFACE AREA INCREASES THE RATE: Examples: - - -

3. CONCENTRATION INCREASED CONCENTRATION INCREASES THE RATE: examples: -

What did father use to great a concentration of when he did the laundry?

4. PRESSURE HIGHER PRESSURE INCREASES THE RATE: Examples: - - -

5. MOLECULE SIZE SMALLER MOLECULES REACT FASTER: examples: - - -

6. CATALYST ADDITION OF A CATALYST CHANGES THE RATE: (A CATALYST IS A MOLECULE THAT SPEEDS UP OR INHIBITS THE SPEED OF A REACTION) examples: - - ENZYME – A CATALYST IN LIVING THINGS

EQUILIBRIUM THE STATE IN WHICH A CHEMICAL REACTION AND ITS REVERSE OCCUR AT THE SAME TIME AND AT THE SAME RATE. EXAMPLE: CO 2 in a closed soda container stays dissolved because it is under pressure.