1. Chemical Bonds And Equation

2. Types Of Chemical Bonds

3. Compound
substance made of the combined atoms of two or more elements.
Chemical formula
tells what elements a compound contains and the exact number of the atoms of those elements

4. Some Common Compounds Vinegar Acetic acid HC2H3O2 Sand Silicon dioxide
SiO2
Stomach Acid
Hydrochloric acid
HCl
Cane Sugar
Sucrose
C12H22O8

5. Superscript
represents oxidation # or how many electrons has gained or lost
2H2O
SO42-
Coefficient
represents the # of units of each substance
Subscripts
represents # of atoms in a molecule of a particular element
Atoms form compounds to become chemically stable. An atom is chemically stable when the outer energy level is complete, or full.

6. Ionic Bond vs. Covalent Bond
Chemical bond
force that holds together the atoms in a substance
ION
positive or negatively charged atom
Ionic Bond vs Covalent Bond
loses or gains electrons
shares electrons
attraction between
opposite charges of ions
can form multiple bonds
between a nonmetal and a
between metal & nonmetals
nonmetal

7. Writing Formulas and Naming Compounds

8. Binary compound
compound composed of two elements
Oxidation number
positive or negative number (on PTable) which indicates how many electrons an element has gained, lost or shared when bonding with another atom.
* When writing a formulas for binary ionic compounds, it is important to remember that compounds formed have a net charge of zero.

9. POLYATOMIC IONS
Charged
Name
Formula 1+
Ammonium
NH4+ 1-
Acetate
C2H3O2-
Chlorate
ClO3-
Hydroxide
OH-
Nitrate
NO3- 2-
Carbonate
CO32-
Sulfate
SO42- 3-
Phosphate
PO43-
Polyatomic Ions a positively or group of atoms negatively charged covalently bonded
The prefix poly means “many”, so the term polyatomic means “having many atoms”

10. Prefixes For Binary Covalent Compounds
Hydrate
a compound that has water chemically attached to its ions and written into chemical formula.
Covalent compounds
can form more than one compound with each other. Scientist use Greek prefixes to indicate # of atoms of each element in binary compound.
Prefixes For Binary Covalent Compounds
#atoms 1 2 3 4 5 6 7 8
prefix
Mono-
di-
tri-
tetra
penta
hexa
hepta
octa

11. Chemical Reactions

12. Chemical reaction - a reaction in which one or more are changed to new substances
Reactants - substances that are about to react
Produced Reactants Products
Products - new substances produced
Law of Conversation of Mass
total starting mass of all reactants equals the total final mass all products.

13. Chemical equation - uses chemical formulas and symbols to describe a chemical reaction and the product it produces (see below)
Symbol
Meaning
produces or yields
(aq)
Aqueous (solid dissolved in H2O) +
plus
Heat
Reactants heated
(s)
solid
Light
Reactants exposed to light
(l)
liquid
Elec
Electric current
(g)
gas
Applied to reactants

14. 4Al (s) + 3O2 (g) 2Al2O3 Coefficients
#’s which represents the number of units of each substance in a rxn
4Al (s) + 3O2 (g) Al2O3
Subscripts
#’s which represent the number of atoms in a molecule of a particular element

15. Balancing Chemical Equations

16. Balanced chemical equations
have the same number of atoms of each element on both sides of equation
* When balancing chemical equation NEVER change the subscripts, instead change the coefficient in front of the compounds needing balanced.

17. Steps to Balancing a Chemical Equation
Step 1: Write a chemical equation for the reaction using formulas and symbols ­­– make sure reactants are on left side and products on right. Step 2: Count the atoms in reactants and products. Step 3: Choose coefficients that balanced the equation. HINT: Generally, if there is an even # of an element on one side and an odd on the other side, place a 2 in front of compound containing odd number of atoms.

18. Ex NaBr + Cl NaCl + Br2
STEP 3
STEP 1 Na Br Cl
STEP STEP 4
Step 4: Recheck the numbers of each atom on both sides of and adjust coefficients if necessary – remember NEVER change subscripts.

19. Chemical RXNS – Types, Rates And Energy

20. Synthesis reaction - reaction where two or more substances combine to form another substance Decomposition reaction - reaction where one substance breaks down, or decomposes, into two or more simpler substances
A+B AB
AB A+B

21. AB + CD AC + BD A + B AC + B or A + BC AB + C
Double – displacement reaction - reaction that results in a precipitate, water or gas when a positive ion of one compound swaps with another positive ion of another compound.
AB + CD AC + BD
Single – displacement reaction - reaction in which one element replaces another in a compound
A + B AC + B or A + BC AB + C

22. Exothermic reactions Endothermic Reactions
Chemical reactions involve energy exchange
Exothermic reactions Endothermic Reactions
reaction in which energy reaction in which heat is released in front of heat energy is absorbed
Ex. burning wood, fireworks Ex. Chemical Ice packs
explode photosynthesis

23. Catalyst
speeds up a chemical reaction without itself being permanently changed
Inhibitor
prevents or slows a chemical reaction or interferes with the catalyst