Transcript Notes #1

Chemistry
Ch 12
Stoichiometry
Notes #1
What is stoichiometry?
• Study of quantitative relationships btwn
amounts of reactants used and products
formed by a chemical reaction
• Based on the law of conservation of
mass
• Chapter 11 math is the basis of the
chapter 12 math – if you don’t get it – ask!
Interpreting equations
• 4Fe (s) + 3O2 (g) -> 2Fe2O3 (s)
– Particles
– Moles
– Mass
Example - interpreting
• N2 (g) + 3H2 (g) -> 2NH3 (g)
– Particles
– Moles
– Mass
Homework
• Interpreting
• 6-14 on side 1 of sg
• Number 1 on the supplemental
• That much should be DONE for tomorrow!
Mole Ratios
• Ratio between the numbers of moles of
any 2 substances in a balanced
chemical equation
• We will be using mole ratios as
conversions factors in future math
problems
• Mole ratios show relationships between
reactants and products in equations
Example – Mole Ratio
• 2Al (s) + 3Br2 (l) -> 2AlBr3 (s)
• How many will there be?
• Number of species x 1 less
• Species = reactants and products
Example – Mole Ratio
•
•
•
•
What is the mole ratio with the biggest value?
What is the mole ratio relating Al to Br?
What is the mole ratio relating the product to Al?
HW – back of SG and #2 on supp