Quantitative Chemistry: Stoichiometry

Maggie LiHannah BenskyEugene KyereElton Luong

1.4.1 Theoretical Yields

•2Na + Cl2 -> 2NaCl•5g Na -> ____g NaCl

5g Na 1mol Na 2mol NaCl 58.44g NaCl 1 22.99g Na 2mol Na 1mol NaCl

1.4.2 Limiting/Excess Reactants

• 2Na + Cl2 -> 2NaCl• Limiting is the one used up first.• Excess is the amount left over

after the limiting reactant is used up.

1.4.3 Percent Yields

• Predicted is what you should have gotten based on theoretical yield (1.4.1). • Actual or experimental is what you got

through physical experimentation.

1.4.4 Avogadro’s Number

• Used to determine particles or atoms per mole as a conversion of any element.

• 6.022x1023 atoms/particles X = 1 mol X

1.4.5 Standard Volume

•1mol X(g) = 22.4L X(g)

•Any element is subject to this in a gaseous state at STP (standard temperature and pressure).

1.4.6 Combined Gas Law

Where p = pressure, V = volume, and T = temperature (K)

1.4.7 Ideal Gas Law

1.4.8 Ideal Gas Graphs

Where A = pressure or volume and B = temperature

Where A = pressure and B = volume

PV=nRT

For the following problems, use the equation given above.1. Given 10g of water, how many grams of oxygen will be produced?2. Which is the limiting reactant if 20g of each reactant is used? How many grams of the excess

is left?3. If 6 moles of carbon dioxide made 176.45g of organic matter, what is the percent yield?4. Calculate the number of water atoms needed to make 12 moles of oxygen.5. If 13 liters of oxygen is given off by a plant, how many grams of sugar was also produced?6. The oxygen in the previous problem was trapped in an airtight container at STP. The pressure

and temperature was then doubled. Assuming the water is vapor, what is the new volume?7. Using the new water volume from the previous problem, calculate the number of moles if

the temperature becomes 356K and the pressure becomes 0.5atm.