Mole Ratios
What units do coefficients use?
Moles
What is the percent yield equation?
actual yield / theoretical yield x 100
3 MgBr2 + 2 FeCl3 —> 3 MgCl2 + 2 FeBr3
I started with 52.6 grams of FeCl3. How many grams of MgCl2 will I make.......which two substances do you care about from this reaction?
FeCl3 & MgCl2
H2SO4
Molar Mass = ?
98.08 g/mol
2 H2O ---> 2 H2 + O2
How many moles does H2 have?
2 moles
Actual yield = 45 g
Theoretical Yield = 52 g
% Yield = ?
86%
Na + Cl ---> NaCl
33.5 g Na = ? g NaCl
85.2 g NaCl
Fe(OH)3
Molar Mass = ?
106.87 g/mol
3 NaCl + FeBr3 ---> 3 NaBr + FeCl3
What is the mole ratio of NaCl & FeCl3
3 moles NaCl / 1 mole FeCl3
Actual Yield = 4.92 g
Theoretical Yield = 33.2 g
% Yield = ?
14.9%
3 Na2O + Al2S3 —> 3 Na2S + Al2O3
98.6 g Na2O = ? g Al2O3
54.1 g Al2O3
Cu3(PO4)2
Molar Mass = ?
380.58 g/mol
2 C4H10 + 13O2 ---> 8 CO2 + 10 H2O
What is the mole ratio for O2 & CO2?
13 moles O2 / 8 moles CO2
In a reaction you calculated that you should make 13.6 grams of a substance by using stoichiometry.
You measured 11.9 grams of the substance when you did the experiement.
What is the % yield?
87.5%
Cu + 2 AgNO3 —> 2 Ag + Cu(NO3)2
123.4 g Cu(NO3)2 = ? g Ag
141.9 g Ag
What do we use mole ratios for?
To convert from one substance to another.
2 AlCl3 + 3 Na2O ---> Al2O3 + 6 NaCl
I started with 33.5 g of AlCl3. How many grams of NaCl should I make?
I ended with 40.5 g of NaCl at the end of the experiment. What is the percent yield?
91.8%
2 KClO3 → 2 KCl + 3 O2
13.9 g KClO3 = ? g O2
5.44 g O2