1. Chemical Equations
Reaction Stoichiometry-the quantitative relationship among
substances as they participate in a chemical reaction.
2Al(s)+ 3Br2(g) Al2Br6(s)
Reactants Products
2Al, 6Br Al, 6Br
s=solid g=gas l=liquid aq=aqueous

2. 2Hg2O(s) Hg(l) + O2(g)
417.2g g+32.0g=232.6g
834.4g g+32.0g=834.4g
Check 4Hg,2O Hg,2O
= Heat

3. Balance the given chemical Rxn
NH3+O2NO+H2O N,3H,2O 1N,2H,2O
2NH3+O2NO+3H2O N,6H,2O 1N,6H,4O
2NH3+O2NO+3H2O N,6H,2O 2N,6H,5O
2NH3+5/2O2NO+3H2O 2N,6H,5O 2N,6H,5O
4NH3+5O2NO+6H2O 4N,12H,10O 4N,12H,10O

4. 2Mg(s)+2HCl(aq) 2MgCl(aq) + H2(g)
2Mg, 2H, 2Cl Mg, 2H, 2Cl

5. 2Mg(s)+2HCl(aq) 2MgCl(aq) + H2(g)
How many moles of HCl will react with 2.3 moles of Mg(s)?
2 moles HCl(aq)
2 moles Mg(s)
2.3 moles Mg * = 2.3 moles HCl
How many moles of H2(g) will be produced if we react 22.3 g of Mg(s)
with excess aqueous HCl?
1 mol Mg(s) 1 mol H2(g)
24.3 g mol Mg(s)
22.3 g Mg(s) * * = mol H2
How many grams of H2(g)?
2.02 g
1 mol H2
mol H2 * = g H2

6. How many sandwiches can you make with 6 pieces of
bread and 4 pieces of cheese?
2 pieces of bread/sandwich 1 piece of cheese/sandwich
6 pieces of bread * 1 sandwich/2pieces of bread = 3 sandwiches
4 pieces of cheese*1 sandwich/1piece of cheese = 4 sandwiches
Therefore, the bread is the limiting factor.

7. Limiting Reactant Concept
What is the maximum mass of sulfur dioxide that can
be produced by the reaction of 95.6 g of carbon
disulfide with 110 g of oxygen?
Therefore, the limiting reagent is the Oxygen

9. Percent Yields from Reactions
Theoretical Yield- what we have been calculating.
Actual Yield - what you have in your flask