Reaction Types
2 Li + Br2 → 2 LiBr
Synthesis
____Al + ____O2 → ____Al2O3
4, 3 and 2
These are used to balance chemical equations
Coefficients
In the following equation, what is the mole ratio of aluminum to hydrogen gas?
2 Al + 6 HCl → 2 AlCl3 + 3 H2
2:3
Why is O2 written as it is, and not as O?
Because it is a diatomic molecule and must be found in 2. It is also a gas.
Zn + CuCl2 → ZnCl2 + Cu
Single Replacement
____Cl2 + ____KI → ____KCl + ____I2
1, 2, 2, 1
The reactant that prevents the reaction from proceeding further.
Limiting reactant
You collect 8.8 g of copper in an experiment. You were supposed to collect 5.7 g. What if your percent yield?
154.4%
What does an up arrow represent in an equation? What about a down arrow?
gas being released
precipitate
____AgNO3 + ____CaCl2 → ____AgCl + ____Ca(NO3)2
Double Replacement
____P + ____O2 → ____P2O5
4, 5, 2
What states that matter can neither be created nor destroyed?
The Law of Conservation of Mass
Actual is collected from lab
Calculated found from stoichiometry
What are at least 3 evidences that a chemical reaction has occurred?
Change in color, change in temperature, change in odor, production of light, precipitate, release of gas
2 Al2O3 → 2 Al + 3 O2
Decomposition
BaCl2 + Mg3(PO4)2 → MgCl2 + Ba3(PO4)2
3, 1, 3, 1
The reactant that is left over after the reaction comes to a stop.
Excess reactant.
Determine the mass of water produced when 6.50 grams of ethene (C2H4) reacts with oxygen.
C2H4 + 3 O2 → 2 CO2 + 2 H2O
8.35 g H2O
You collect 0.3 g of oxygen gas. You clumsily let some escape because you were supposed to collect 1.9 g. What is your percent yield?
15.8%
C3H6 + O2 → CO2 + H2O
Combustion
____CH4 + ____O2 → ____CO2 + ____H2O
1, 2, 1, 2
Percent yield
If 2.56 g of Al is reacted, what mass of zinc is produced?
2 Al + 3 ZnCl2 → 3 Zn + 2 AlCl3
9.30 g Zn
What is a practical application of stoichiometry?
Answers will vary.