1. 7.1 Stoichiometry Objective 2
Chemistry

2. Essential Questions What is stoichiometry?
How can you relate moles of two different compounds?
How do you relate mass and liters of two different compounds?

3. Stoichiometry
Study of quantitative (measurable) relationships in formulas of a reaction
N2H4 + 2H2O2 → N2 +4 H2O
Coefficients tells us how many individual particles, but it can also represent how many MOLES of a substance we have
ALWAYS start with a complete BALANCED EQUATION!!

4. Molar Ratios
Using coefficients we can relate the number of moles of compounds to one another with molar ratios
Ex: 2 CuO + C → 2 Cu + CO2
Find the number of mol of CuO when you have 5.0 mol C.
# mol want # = coefficient
# mol given
= 10 mol CuO

5. Mole to Mole Relationships
NH4NO3 → N2O + 2H2O
If we had 2 mol NH4NO3
How many moles N2O are produced?
How many moles water are produced?
2KClO3  2K + Cl2 + 3O2
If you have 7.25 mol KClO3
How many moles Cl2?
How many moles O2?

6. Mass to Mass conversion
When given the mass of one substance and are asked to find the mass of another.
There is not a direct relation between the mass of different substances. WHY?
Mass Of Given (g)
Moles Of Want
Moles Of Given
Mass Of Want (g)
1 mol given___
molar mass given
molar mass want
1 mol want
# mol want_
# mol given
# = coefficient

7. Molar Conversion
Answer the following questions for this equation Na2SO4 + 2KCl → 2NaCl + K2SO4
Find the number of mol of KCl for 7.00 mol of Na2SO4
Find the mass of NaCl for 2.5 mol of KCl
Find the mol of K2SO4 for 125 g of KCl
Find the mass of Na2SO4 given that there are 75 g of NaCl
14.0 mol KCl
146 g NaCl

8. Molar Conversion (cont)
Answer the following questions for this equation CH4 + 2 O2 → CO2 + 2 H2O
Find the number of mol of CO2 for 200. g of O2
Find the mass of CH4 for 5.0 mol of H2O
Find the mass of O2 for 100. g of CH4

9. Mass to Volume Problems
Mass Of Given (g)
Moles Of want
Moles Of Given
Volume Of Want (L)
22.4 L want
1 mol want
1 mol given___
molar mass given
# mol want_
# mol given
# = coefficient

10. Practice Problems
Balance the following equation and use it to answer the questions
NaHCO3 → Na2O + H2O + CO2
If you have 3.3 mol Na2O how many liters of H2O vapor did you produce?
If you have 4.0g of NaHCO3 what volume of CO2 at STP will be produced?
If you have 36.9 g H2O what volume of CO2 did you produce?

11. Volume to Volume Problems
Volume Of Given (L)
Moles Of Want
Moles Of Given
Volume Of Want (L)
22.4 L want
1 mol want
1 mol given___
22.4 L given
# mol want_
# mol given
# = coefficient

12. Answer the questions according to the following equation
Practice Problems
Answer the questions according to the following equation
H2 + Cl2 → HCl
0.38 L of H2 reacts to form what volume of HCl gas?
If you have 2.7 L of HCl how many liters of H2 do you have?

13. Essential Questions What is stoichiometry?
How can you relate moles of two different compounds?
How do you relate mass and liters of two different compounds?

14. 7.1 Tracked Assignment
P #40-42, 44 (not b), 49