1 CHEMICAL REACTION PROCESS IN WHICH OLD BONDS ARE BROKEN AND NEW BONDS ARE FORMED TO REARRANGE ATOMS

2 CHEMICAL EQUATION DESCRIPTION OF A CHEMICAL REACTION SHOWING WHAT SUBSTANCES ARE CONSUMED, WHAT SUBSTANCES ARE PRODUCED, HOW MANY MOLECULES OF EACH SUBSTANCE, AND WHAT IS THE PHASE OF EACH SUBSTANCE

3 EXAMPLE EQUATION 2H 2 O (l)  2 H 2(g) + O 2(g)  MEANS PRODUCES OR YIELDS SUBSTANCES ON TAIL SIDE ARE CALLED REACTANTS (THESE REACT) SUBSTANCES ON THE HEAD SIDE ARE CALLED PRODUCTS (MADE FROM THE REACTANTS)

4 UNBALANCED EQUATION H 2 + O 2  H 2 O THIS IS UNBALANCED BECAUSE THE NUMBER OF ATOMS ON BOTH SIDES IS NOT EQUAL

5 LAW OF CONSERVATION OF MATTER ATOMS CANNOT BE CREATED OR DESTROYED IN A CHEMICAL REACTION # OF ATOMS OF EACH ELEMENT ON REACTANT SIDE = # OF ATOMS OF EACH ELEMENT ON PRODUCT SIDE MASS OF REACTANTS = MASS OF PRODUCTS

6 FORMS OF ENERGY KINETIC IS ENERGY OF MOVING THINGS POTENTIAL IS ENERGY POSSESSED DUE TO POSITION (ELEVATED OR IN A ELECTRIC OR MAGNETIC FIELD)

7 LAW OF CONSERVATION OF ENERGY ENERGY CANNOT BE CREATED OR DESTROYED IN ANY PROCESS ENERGY MIGHT BE GIVEN OFF OR ABSORBED IN A CHEMICAL REACTION, BUT TOTAL ENERGY IS CONSTANT

8 BALANCING AN EQUATION ADD COEFFICIENTS # OF ATOMS OF EACH ELEMENT IS SAME ON BOTH SIDES, MUST BE SMALLEST POSSIBLE DO NOT CHANGE SUBSCRIPTS! COEFFICIENTS MULITPLY ALL SUBSCRIPTS OF THE COMPOUND THEY PRECEDE 2H 2 + 1O 2  2H 2 O

9 PHASES PHASES ARE INDICATED BY LETTER SUBSCRIPTS IN PARENTHESES SOLID – (s) LIQUID – (l ) GAS – (g) WATER SOLUTION – (aq)

10 ENERGY SHOW ENERGY AS A PRODUCT TO INDICATE A REACTION IS EXOTHERMIC SHOW ENERGY AS A REACTANT TO INDICATE A REACTION IS ENDOTHERMIC HEATING IS SHOWN BY A TRIANGLE ABOVE THE ARROW (DON’T ALSO SHOW ENERGY AS REACTANT)

11 6 TYPES OF REACTIONS SYNTHESIS (COMBINATION) DECOMPOSITION COMBUSTION SINGLE REPLACEMENT DOUBLE REPLACEMENT ACID-BASE

12 COMBINATION ALSO CALLED SYNTHESIS FORM: X + Y  XY NUMBER OF REACTANTS > NUMBER OF PRODUCTS

13 COMBINATION EXAMPLES 2H 2 + O 2  2H 2 O 2Al + 3S  Al 2 S 3 MgO + CO 2  MgCO 3 P 2 O 5 + 3H 2 O  2H 3 PO 4

14 DECOMPOSITION FORM: XY  X + Y SINGLE REACTANT TWO OR MORE PRODUCTS

15 DECOMPOSITION EXAMPLES H 2 CO 3  H 2 O + CO 2 2Al 2 O 3  4Al + 3O 2 Na 2 CO 3  CO 2 + Na 2 O 2H 2 O  2H 2 + O 2 (DECOMPOSITION OF WATER BY AN ELECTRIC CURRENT IS CALLED ELECTROLYSIS)

16 COMBUSTION FORM: X + O 2  XO MAY HAVE SEVERAL PRODUCTS, ALL WILL BE OXIDES VERY RAPID REACTION ALWAYS EXOTHERMIC IF X IS A HYDROCARBON, PRODUCTS WILL BE CO 2 + H 2 O

17 COMBUSTION EXAMPLES 2H 2 + O 2  2H 2 O 2Mg + O 2  2MgO CH 4 + 2O 2  CO 2 + H 2 O C 3 H 8 + 5O 2  3CO 2 + 4H 2 O

18 SINGLE REPLACEMENT FORM: E + XY  EY + X OR XE + Y DEPENDING ON WHETHER E IS A METAL OF NONMETAL XY IS OFTEN AN IONIC COMPOUND LIKE REPLACES LIKE: METAL FOR METAL, NONMETAL FOR NONMETAL AN ELEMENT CAN ONLY REPLACE A LESS ACTIVE ELEMENT

19 ACTIVITY SERIES LIST OF ELEMENTS IN ORDER OF DECREASING REACTIVITY CAN REPLACE ANY BELOW IT

20 EXAMPLE SR REACTIONS 2K + H 2 O  2KOH + H 2 3Na + AlCl 3  3NaCl + Al F 2 + 2NaBr  2NaF + Br 2 Fe + CuSO 4  FeSO 4 + Cu

21 DOUBLE REPLACEMENT FORM: AB (aq) + XY (aq)  AY + XB BOTH REACTANTS ARE IONIC COMPOUNDS ONE PRODUCT MUST BE INSOLUBLE SOLID, INSOLUBLE GAS, OR MOLECULAR COMPOUND

22 PRECIPITATE INSOLUBLE SOLID FORMED BY REACTION OF AQUEOUS SOLUTIONS FALLS TO THE BOTTOM OF THE REACTION VESSEL (GIVEN ENOUGH TIME) INDICATED BY DOWN ARROW

23 EXAMPLE DR REACTIONS BaCl 2(aq) + Na 2 SO 4 (aq)  BaSO 4(s)  + 2NaCl (aq) Pb(NO 3 ) 2 (aq) + 2NaI (aq)  PbI 2(s)  + 2NaNO 3 (aq)

24 ACIDS, BASES & SALTS ACIDS PRODUCE H + IONS WHEN DISSOLVED IN WATER BASES PRODUCE OH - IONS WHEN DISSOLVED IN WATER SALT IS AN IONIC COMPOUND FORMED FROM THE CATION OF A BASE AND THE ANION OF AN ACID

25 ACID - BASE REACTIONS FORM: HY (aq) + XOH (aq)  H 2 O + XY (aq) XY IS A SALT ACID BASE REACTIONS ARE SIMILAR TO DOUBLE REPLACEMENT REACTIONS

26 ACID - BASE EXAMPLES HCl (aq) + KOH (aq)  KCl (aq) + H 2 O (l) H 2 CrO 3(aq) + NaOH (aq)  Na 2 CrO 3(aq) + H 2 O (l)

27 PREDICTING PRODUCTS LEARN THE FORM OF EACH REACTION TYPE USE THE KNOWN SUBSTANCES TO DETERMINE WHICH FORM THEY FIT TO KNOW THE REACTION TYPE FILL IN MISSING PRODUCTS INVOLVING ELEMENTS NOT ALREADY IN SOMETHING

28 PREDICTING EXAMPLES WRITE A BALANCED EQUATION FOR THE REACTION –BETWEEN Ca (s) and F 2(g) –OF KClO 3(s) (ONLY REACTANT) –BETWEEN Mg (s) AND H 2 SO 4(aq) –BETWEEN LiOH (aq) AND HCl (aq) –BETWEEN Na 2 S (aq) AND Pb(NO 3 ) 2(aq) –OF BURNING C 4 H 10(g)

29 REACTION RATES REACTION RATE IS THE SPEED AT WHICH A REACTION OCCURS AFFECTED BY 4 FACTORS

30 4 FACTORS SURFACE AREA OF THE REACTANTS CONCENTRATION OF REACTANTS TEMPERATURE OF THE REACTANTS/ENVIRONMENT PRESENCE OF A CATALYST OR INHIBITOR

31 SURFACE AREA REACTIONS OCCUR AT THE SURFACE OF SUBSTANCES THE MORE SURFACE AREA, THE FASTER THE REACTION SOLID CAN BE POWDER, CHUNKS, OR A LUMP (FROM MOST SURFACE AREA TO LEAST FOR THE SAME MASS)

32 CONCENTRATION RECALL CONCENTRATION IS THE AMOUNT OF SUBSTANCE IN A GIVEN VOLUME HIGHER CONCENTRATIONS MEAN MORE SUBSTANCE IS PRESENT, SO THE REACTION WILL OCCUR FASTER

33 TEMPERATURE WHEN SUBSTANCES HAVE MORE ENERGY, THEY WILL HAVE A HIGHER TEMPERATURE AND THEIR ATOMS/MOLECULES WILL MOVE QUICKER THIS ALLOWS MORE COLLISIONS AND A FASTER REACTION

34 CATALYST/INHIBITOR CATALYST - A SUBSTANCE THAT SPEEDS UP A REACTION WITHOUT BEING PERMANENTLY ALTERED ITSELF INHIBITOR – A SUBSTANCE THAT SLOWS DOWN A REACTION WITHOUT BEING PERMANENTLY ALTERED