Formulas and Equations

AIM# 1: How can we build compounds based on their charges? Types of Chemical Formulas 1.Empircial Formulas : simplest ratio Ionic formulas are always empirical formulas Examples are CO2, H2O, CH4, KCl

2. Molecular formula: actual ratio Gives the number of atoms in each element of the compound Examples: C6H12O6 – which is six times the empirical formula CH2O 3. Structural formula: the arrangement of the atoms in a compound

Practice Determine the number of atoms in the following examples   1. CaCO3 3. KCl 2. Zn3(PO4)2 4. Ag2SO3

***Remember compounds must be neutral*** Atoms and compound are electrically neutral – equal numbers of negative (electrons) and positive (protons) Ions Cations are positive Anions are negative Polyatomic Ions: group of atoms that have covalent and ionic bonds possessing a charge (Found on Table E) ***Remember compounds must be neutral*** For many elements, the oxidation state is equal to the charge found in the top right corner of each element box.

a. Sodium and Chlorine b. Potassium and Oxygen c. Magnesium and Fluorine d. Aluminum and Oxygen e. Lithium and Sulfur f. Potassium and Phosphorus Aluminum and Bromine Barium and Carbonate Sodium and Nitrate j. Ca+2 F- k. NH4+ O-2 l. Ag+ S-2

AIM # 2: How do we name compounds? Remember an Ionic Compound consists of a metal & nonmetal (1st element) Metal is named first retains its name (2nd element) Nonmetal – change ending to “ide” KCl : CaBr2 :

Be mindful of the “odd” sounding elements: Oxygen (Oxide) Hydrogen (hydride) Sulfur (sulfide) Carbon (carbide) and Nitrogen (nitride) PRACTICE: MgO __________________________________________ Ag3N _________________________________________ LiI ____________________________________________ BaF2 _________________________________________ SrO ___________________________________________

Ternary Ionic Compounds- these typically contain Polyatomic Ions Easy to name! The metal and polyatomic ion retains its name! Examples: KNO3 _____________________________________________ NH4NO3 ___________________________________________ Mg(SO4)___________________________________________ Ca(OH)2 ___________________________________________ Li3(PO4)____________________________________________

AIM # 3: How do we name covalent compounds? Remember a covalent (molecular) compounds consists of non- metals Since most of the nonmetals have more than one oxidation state, we have to use prefixes. Molecular Prefix # of atoms    1  2  3  4  5  6

The prefix is used to state the number of atoms of each element The prefix is used to state the number of atoms of each element. The first element retains its name, while the second element will change the ending to -ide The prefix mono is only used for the second element of the compound, not the first. Practice  1. P2O5   2. CO2

Name the following covalent compounds 1 Name the following covalent compounds 1. CI4 ____________________________________ 10. ICl5 _________________________________ 2. PCl5 ___________________________________ 11. H2S3 ________________________________ 3. SI6 _____________________________________ 12. N2O3 ________________________________ 4. P2S6 ___________________________________ 13. SO3 ___________________________________ 5. N3O4____________________________________ 14. NI5 ____________________________________ 6. SO2 _____________________________________ 15. BN2 ____________________________________ 7. N2O4 ___________________________________ 16. P2O5 ___________________________________ 8. CO ________________________________________________ 9. NF3 ______________________________________________

AIM # 4:How do we label components of a chemical equation? What pieces of information can we receive from a chemical equation? CH4 (s) + 2O2 (g) -------- CO2 (g) + 4H2O (l) + energy

Let’s define these terms Reactants Products 3. Yield sign 4. Coefficient

5. Subscripts 6. States of Matter 7. Presence of Energy

Law of Conservation Mass is neither created or destroyed in a chemical reaction, only transformed. *** Mass, atoms, charge, energy*** _____ H2 (g) + ______ O2 (g) → ______ H2O (g)

Remember mass must also be conserved, another way to answer these questions is below If 103.0g of potassium chlorate are decomposed to form 62.7g of potassium chloride and oxygen gas according to the equation 2KClO3  2KCl + 3O2 how many grams of oxygen are formed?

AIM#7: What are the different types of chemical reactions? 1. Synthesis Two or more reactants form one product A + B → AB Potassium + Bromine  Potassium Bromide ______________________________________________ 2. Decomposition One reactant breaks down into two or more products AB → A + B Silver Oxide  Silver + Oxygen _______________________________________________

3. Single Replacement Reaction One element on the reactant side replaces another in the product side A (element) + BX (compound) → B (element) + AX (compound) Zn + CuCl2  Cu + ZnCl2

4. Double Replacement AgNO3 + NaCl  AgCl + NaNO3 Two elements/polyatomic ions replace two others AB (compound) + CD (compound) → AD (compound) + CB (compound) AgNO3 + NaCl  AgCl + NaNO3

A. The product is INSOLUBLE Using the Solubility Chart (Table F) to determine solubility. One of the products has to be soluble, meaning it will dissolve in water. This is an aqueous solution (aq). The other product has to be insoluble, meaning it cannot dissolve in water. This is a precipitate (s). Using the chart, cross out the first element, look for the second element, see if its paired with an exception. NH4Cl  Mg(OH)2 Soluble Insoluble

1. AgNO3(aq) + NaCl(aq)  AgCl(_____) + NaNO3(____) 2 1. AgNO3(aq) + NaCl(aq)  AgCl(_____) + NaNO3(____) 2. BaCl2(aq) + Na2CO3(aq)  3. Zn(NO3)2 (aq) + KOH(aq) 

B. WATER is one of the products HF + NaOH  HNO3 + KOH  H2SO4 + LiOH 

C. One of the products is an INSOLUBLE GAS H2CO3 (aq)  H2O + ____________________________ H2SO3(aq)  H2O + ___________________________ NH4OH (aq)  H2O + ____________________________