March 6, 2015
Pick up turned back docs
2. Pick Up Calculator
1.
Warm up
Using the Sticky Note on your desk
answer the following:
For the Unit Mole Conversions
1. I am strongest at
___________________
2. The question I still have is
________________________
Homework 3-6
Finish Empirical and Molecular
Handout
Important Dates
Monday 3-2 – Smore Chemistry
Tuesday 3-3 – ACT (homeroom)
Wednesday 3-4 – Demo / Reaction Stoich
Thursday 3-5 – Quiz / #TBT
Friday 3-6 – Composition Stoich / Mole
conversion assessment
Today is March 6, 2014
Topic: Reaction Stoichiometry
Lesson Objectives:
SWBAT achieve 85% or higher on their mole
conversion assessment
Essential Question: 2.2 Analyze chemical
reactions in terms of quantities, product
formation, and energy.
Agenda 3-6
Do Now
2 Practice Problems
Assessment
 Composition Stoich Guided Notes
HW Headstart
Mole Conversion Review
How many grams are in 6 moles of Iron?
How many atoms are in 45 grams of water ?
Test
Today is March 6, 2014
Topic: Composition Stoichiometry
Lesson Objectives:
SWBAT to determine the composition of a substance
using multiple composition stoich methods
Essential Question: 2.2 Analyze chemical
reactions in terms of quantities, product
formation, and energy.
Calculating Percentage
Composition
Calculate the percentage composition of
magnesium carbonate, MgCO3.
Formula mass of magnesium carbonate:
24.31 g + 12.01 g + 3(16.00 g) = 84.32 g
 24.31 
Mg  
  100  28.83%
 84.32 
 12.01 
C 
  100 14.24%
 84.32 
 48.00 
O 
  100  56.93%
 84.32 
100.00
Practice
1.
2.
3.
H2O (calculate O)
CaCOOH (Calculate Ca)
NaOH (Calculate H)
Empirical Formula
The formula that gives the simplest whole-number
RATIO of the atoms of each element in a compound
“Simplified”
Empirical Formula
Chemical Formula
(Molecular Formula)
H 2 O2
C6H12O6
CH3O
C2H4O2
Empirical Formula
HO
Determining Empirical Formulas
Steps:
1. Find mole amounts
2.
Divide each mole by the
smallest mole
3.
Multiply until all whole
numbers
1. Percent to mass
2.Mass to Mole
3.Divide by small
4.Multiply ‘till
whole
Determine the empirical formula for a
compound containing 2.128g Cl and
1.203g Ca
Molecular Formula
The formula that gives the ACTUAL NUMBER of
atoms of each element in a compound
“Real Life”
Determining Molecular Formula
Steps:
1. Find the empirical formula
2. Calculate the empirical formula mass or “EFM” (think
molar mass)
3. Divide the molar mass by the “EFM” (this gives you
the “factor”)
4. Multiply empirical formula by the factor
Find the molecular formula for a
compound who molar mass is ~124.06 and
empirical formula is CH2O3