1. Chemistry – Apr 9, 2019 P3 Challenge –
Get out Empirical Formula Worksheet for HMK check
P3 Challenge –
Determine the Empirical Formal for a compound that contains % potassium, % manganese and % oxygen.
Today’s Objective –
Moles and Chemical formulas
Agenda
Hmk Review
Pair vs Pair competition
Moles and Chemical formulas (time permitting)
Assignment:
Chemical Formula Worksheet

2. Homework Ans. only 1. 28.45% Cu 71.55% Br
% Na % O 2.52% H
% N % H % S
% N % S
% K % Mn % O
% H % Cl
% Mg % N % O
% N % H % O % P
% Al % S % O
10. FeSO3 iron(II) sulfite
11. CrCl3 chromium (III) chloride
12. TlC2H3O2 Thallium (I) acetate
13. ZnO Zinc oxide
14. C5H3O2N2
15. C4H5ON2 C8H10O2N4
16. HO H2O2
17. O3C3N3Cl3
18. C5H7N C10H14N2

3. Practice in teams of 2-3
Create problem for another team using a worksheet. (to be handed in)
Pick a compound. (Keep it a secret from your other team.)
Determine the molar mass of your compound.
Find the percentage of elements in your compound. (Double check for accuracy)
Exchange your lists of a) molar mass, b) elements, c) mass percents on P3 paper
Determine your mystery compound
Convert your list of percents and molar mass to a chemical formula.
Check your answer with your challengers
Turn in your P3 paper questions and answers complete with your names and the names of your challengers.

4. Chemical Formulas and Conversion Factors
Because the chemical formula indicates the number and ratio of atoms in a compound, conversion factors can be written to convert between moles of atoms and moles of compounds.
Ex: 1 mole CO2 contains 1 mole of C and 2 mole of O
Ex: How many moles of O are present in 3.25 mol of H3PO4?

5. Gram – mole –number of items problems
Grams of X
Moles of Y
Grams of Y
Moles of X
Not Here!!
Molar mass
Chemical formula
Number of X
Number of Y
6.022x1023
Atomic scale
Macroscopic scale
Liters of X
22.4

6. Gram – mole problems using the chemical formula
Grams of CO2
Ex: Determine the number of moles of CO2 in a 15.0 g sample of CO2.
Ex: What mass does 1.25 moles of CO2 have?
Molar mass
44.01 g/mol
Moles of CO2

7. Gram – mole problems using the chemical formula
Moles of CO2
Moles of C
or O
Ex: Determine the number of moles of C in 8.30 mole of CO2.
Ex: Determine the number of moles of O in mole of CO2.

8. Gram – mole problems using the chemical formula
Grams of CO2
Ex: Determine the number of moles of C in 15.0 g of CO2.
Ex: Determine the number of moles of O in 15.0 g of CO2
Molar mass
44.01 g/mol
Moles of CO2
Chemical formula
Moles of C
or O

9. Gram – mole problems using the chemical formula
Grams of CO2
Grams of C, O
Molar mass
44.01 g/mol
Molar mass
12.01 g/mol, g/mol
Chemical formula
Moles of CO2
Moles of C, O
Ex: Determine the number of grams of a)carbon and b)oxygen in g of CO2.

10. Gram – mole – number problems using a chemical formula
Grams of X
How many copper atoms are present in a gram sample of copper (I) oxide, Cu2O?
Molar mass
g/mol
Moles of X
Chemical formula
Moles of Y
Macroscopic scale
Atomic scale
Number of Y

11. Gram – mole –number of items problems
Grams of X
Moles of Y
Grams of Y
Moles of X
Not Here!!
Molar mass
Chemical formula
Number of X
Number of Y
6.022x1023
Atomic scale
Macroscopic scale
Liters of X
22.4

12. Exit Slip - Homework
Exit Slip: How many grams of silver are present in 23.5 g of silver nitrate?
What’s Due? (Pending assignments to complete.)
Chemical Formula worksheet
What’s Next? (How to prepare for the next day)
Read p , p , 241 p