Basics
What step does every stoich problem have?
Mole Ratio
Fe+O2--->Fe2O3
Find the mole ratio of Iron to Oxygen (This is unbalanced)
4:3
The amount of product that a chemist measures in the lab during an experiment.
Actual Yield
Where do you find the numbers for the mole ratio?
Coefficients of a balanced chemical equation
Fe3O4 + 4 CO--->3 Fe + 4 CO2
How many moles of Fe3O4 will form from 5.0 moles of Fe?
1.67 moles Fe3O4
Maximum amount of a product that can be given off. Calculated with stoich.
Theoretical Yield.
The reactant that "runs out" first is known as the what?
Fe3O4 + 4 CO--->3 Fe + 4 CO2
How many moles of CO are needed to react with 16.5 g of Fe3O4
0.285 moles CO
If a student's actual yield was 32g and their theoretical yield was 30g, what is their percent yield?
106.67%
How do you find how much excess reactant is left over?
Starting amount of excess reactant - how much excess reactant was used
How much excess reactant is left over from 1.25 mols of chlorine gas reacting with 2 mols sodium to form sodium chloride?
0.25 mol Cl2
What is one possible reason a student's percent yield could be over 100%?
They measured something they did not intend to/product was contaminated
They measured out too much of their reactants when they ran the experiment.
If we were converting mL of A to grams B, what is the general outline of the stoich set up?
Given mL A → mL to L → molarity A → mole ratio → molar mass B
Ammonium nitrate decomposes into dinitrogen monoxide gas and water. Determine the amount of water produced if 25.0 g of ammonium nitrate decomposes.
11.3grams H2O
A student reacted 6g nitrogen with excess hydrogen and collected 5g of NH4. What is their percent yield?
68.5%