1. Aim: How can the amount of product be predicted?
Do Now:
Take out a calculator and reference tables.
Label the following reactions as synthesis, decomposition, single replacement or double replacement.
Zn + 2HCl  ZnCl2 + H2
2NaClO3  2NaCl + 3O2
P4 + Cl2  PCl3
2HNO3 + Mg(OH)2  Mg(NO3)2 + 2H2O

2. *** Reminder *** What does the law of conservation of matter say?
The number of atoms on each side of a chemical reaction must be equal.
How can we use this information? We can use this information to determine the amount of product created or the amount of reactants used.
Problems solved with this information include:
Mole-mole problems
Mole-mass problems
Mass-mass problems
Mass – volume problems
Volume – volume problems

3. Mole – Mole Problems
Answers how many moles of one element or compound react with a given number of moles of another compound.
Example: How many moles of Ca are needed to react completely with 6 moles of H2O in the following reaction:
Ca + 2H2O  Ca(OH)2 + H2

4. Practice Problems
Given the reaction: 2CO2 + O2  2CO2 What is the minimum number of moles of O2 required to produce 1mole of CO2?
Given the reaction: 2KClO3  2KCl + 3O2 What is the total number of moles of KClO3 needed to produce 6 moles of O2?
Given the reaction:
2NaOH + H2SO4  Na2SO4 + 2H2O What is the total number of moles of NaOH needed to react completely with 2 moles of H2SO4?
CO2

5. Mole – Mass Problems
Answer how many grams of reactants or products are used/created within a specific formula.
Example: If 103.0g of KClO3 are decomposed to form 62.7g of KCl and O2 gas according to the equation 2KClO3  2KCl + 3O2 how many grams of oxygen are formed?

6. Practice Problems
What mass of carbon dioxide will be produced if 144g of carbon react with 384g of oxygen gas according to the equation C + O2  CO2?
How many grams of silver nitrate are needed to react with 156.2g of sodium sulfide to produce 595.8g of silver sulfide and 340.0g of sodium nitrate according to the equation
2AgNO3 + Na2S  Ag2S + 2NaNO3?

7. Mass – Mass Problems
Give you the grams of one element or compound and ask you to find the grams of another element or compound using the equation given.
Example: How many grams of calcium are needed to react completely with 108 grams of H2O in the equation
Ca + 2H2O  Ca(OH)2 + H2

8. Mass – Volume Problems
Deals with one element or compound in grams and one element or compound in millilters or liters.
Example: How many liters of N2 will react with 36g of H2 at STP given the equation N2 + 3H2  2NH3

9. Volume – Volume Problems
Gives you liters or milliliters of one element or compound and asks you to find liters or milliliters of the other compound or element. (Use the same unit while solving).
Example: What is the total number of liters of carbon dioxide formed by the complete combustion of 28 liters of C2H6 using the equation
2C2H6 + 7O2  4CO2 + 6H2O

10. Activity/Homework
Complete the regents questions on the back of today’s notes.