A. Mole to Mole
What all stoichiometric problems must start with.
What is a balanced equation?
What two conversion factors are needed for moles to mass calculations. (What are the two steps needed to go from moles of one substance to mass of another substance?)
What is the mole ratio and molar mass of the unknown compound.
The three components needed to convert mass of one substance to mass of another substance.
What is the molar mass of the given compound, mole ratio, and molar mass of the unknown compound?
The name of the reagent that runs out first in a chemical reaction.
What is the limiting reactant?
The amount of product that is derived experimentally.
What is the actual yield?
The components of a balanced equation that represent the number of moles/mole ratio.
What are the coefficients?
The formula of aspirin is C9H8O4. What is the molar mass of aspirin?
What is 180.159 g/mol?
9 x 12.011 = 108.099 g/mol
8 x 1.008 = 8.064 g/mol
4 x 15.999 = 63.996 g/mol
108.099 + 8.064 + 63.996 = 180.159 g/mol
The molar mass of Al(OH)3.
What is 78.003 g/mol.
1 x 26.982 = 26.982 g/mol
3 x 15.999 = 47.997 g/mol
3 x 1.008 = 3.024 g/mol
Add: 26.982 + 47.997 + 3.024 = 78.003 g/mol
What is the theoretical yield?
What does a percent yield of 100% mean?
What is a perfect reaction with no loss or gain of product.
What is the mole ratio between aluminum oxide and aluminum in the following equation? (Hint: check balancing)
Al2O3 🡪 Al + O2
For every 2 moles of Al2O3, there are 4 moles of aluminum.
2 Al2O3 = 4 Al + 3 O2
4 NH3 + 3 O2 🡪 2 N2 + 6 H2O
How many grams of nitrogen are produced when 3.89mol of oxygen are used?
What is 72.6 grams of nitrogen.
3.89 molO2 x (2 molN2 / 3 molO2) = 2.5933 molN2
2.5933 molN2 x (28.014 gN2 / 1 molN2) = 72.6 gN2
4 NH3 + 3 O2 🡪 2 N2 + 6 H2O
How many grams of nitrogen are produced if 14.7 grams of ammonia (NH3) are used.
What is 12.1 grams of N2.
14.7 gNH3 x (1 molNH3 / 17.031 gNH3)= 0.8613 molNH3
0.8613 molNH3 x (2 molN2 / 4 molNH3) = 0.4316 molN2
0.4316 molN2 x (28.014 gN2 / 1 molN2) = 12.1 g N2
2 Al + 3 Cl3 🡪 2 AlCl3
What mass of aluminum chloride could be made from 8.1 grams of aluminum and 12.9 grams of chlorine.
What is 16.2 grams of AlCl3.
Mass to mass of 8.1 gAl to AlCl3 = 40.0 gAlCl3
Mass to mass of 12.9 gCl2 to AlCl3 = 16.2 AlCl3
The equation for percent yield.
What is % Yield = (actual yield / theoretical yield ) x 100% ?
14 KMnO4 + 4 C3H5(OH)3 🡪 7 K2CO3 + 7 Mn2O3 + 5 CO2 + 16 H20
If 1.37 mol of KMnO4 were used, how many moles of water would be produced?
What is 1.57 moles of H20?
1.37 molKMnO4 x (16 molH2O / 14 molKMnO4) = 1.57 molH20
4 NH3 + 3 O2 🡪 2 N2 + 6 H2O
If 97.3 grams of H2O are produced, how many moles of ammonia (NH3) were used?
What is 3.60 moles of NH3.
97.3 g H2O x (1 molH2O / 18.015 gH2O) = 5.401 mol H2O
5.401 mol H2O x (4 molNH3 / 6 molH2O) = 3.60 molNH3
Al4C3 + 12 H2O 🡪 3 CH4 + 4 Al(OH)3
How many grams of Al4C3 are needed to react with 9.33 grams of water?
What is 6.21 grams of Al4C3.
9.33 gH2O x (1 molH2O / 18.015 gH2O) = 0.5179 molH2O
0.5179 molH2O x (1 molAl4C3 / 12 mol H2O) = 0.043158 molAl4C3
0.043158 molAl4C3 x (143.961 gAl4C3 / 1 molAl4C3) = 6.21gAl4C3
C2H4 + 3 O2 🡪 2 CO2 + 2H2O
What is the excess reactant if 2.70 moles of ethene (C2H4) react with 6.30 moles of oxygen to produce water?
What is oxygen?
2.70 molC2H4 x (2 molH2O / 1 molC2H4) = 5.40 molH2O
6.30 molO2 x (2 molH2O / 1 molC2H4) = 12.6 molH2O
Excess is O2
C6H6(l) + Cl2(g) 🡪 C6H5Cl(s) + HCl(g)
When 36.8g of C6H6 reacts with an excess of chlorine gas, the theoretical yield of C6H5Cl is 53.0g. If 48.8g are actually produced, what is the percent yield?
What is 92.1% ?
Balance: C3H8 + O2 🡪 CO2 + H20
If 0.881 moles of oxygen (O2) are used, how many moles of water are produced?
What is 0.705 mol H2O?
C3H8 + 5 O2 🡪 3 CO2 + 4 H20
0.881 molO2 x (4 molH2O / 5 molO2) = 0.705 molH2O
2 Na3PO4 + 3 BaCl2 🡪 Ba3(PO4)2 + 6 NaCl
If 14.7 grams of barium phosphate are produced, how many moles of barium chloride were used?
What is 0.0733 moles of BaCl2.
14.7 gBa3(PO4)2 x (1 molBa3(PO4)2 / 601.924 gBa3(PO4)2) = 0.02442 molBa3(PO4)2
0.02442 molBa3(PO4)2 x (3 mol BaCl2 / 1 molBa3(PO4)2) = 0.0733 molBaCl2
2 HNO3 + Mg(OH)2 🡪 Mg(NO3)2 + 2 H2O
How many grams of magnesium hydroxide (Mg(OH)2) are needed to react with 12.3 grams of nitric acid (HNO3)
What is 5.70 grams of magnesium hydroxide.
12.3 gHNO3 x (1 molHNO3 / 62.985 gHNO3) = 0.19528 molHNO3
0.19528 molHNO3 x (1 molMg(OH)2 / 2 molHNO3) = 0.09764 molMg(OH)2
0.09764 molMg(OH)2 x (58.319 gMg(OH)2 / 1 molMg(OH)2) = 5.70 gMg(OH)2
AgNO3 + NaCl = AgCl + NaNO3
What mass of AgCl is produced when 53.42 grams of AgNO3 react with 14.19 grams of NaCl?
What is 38.4 grams of AgCl?
Coming from #1 on Limiting Reactants Packet (We've done this together!)
CO(g) + 2H2(g) 🡪 CH3OH(l)
If 37.0g of CO reacts to produce 38.4g of CH3OH, what is the percent yield of CH3OH?
What is 90.7% ?
37.0 gCO x (1 molCO / 28.01 gCO) = 1.32096 molCO
1.32096 molCO x (1 molCH3OH / 1 molCO) = 1.32096 molCH3OH
1.32096 molCH3OH x (32.042 gCH3OH / 1 molCH3OH) = 42.3 gCH3OH
% yield = (38.4 gCH3OH / 42.3gCH3OH) x 100% = 90.7%