stoichio metry
DESCRIPTION
Element. Measure. Stoichio metry. 2 H 2 + O 2 2 H 2 O. 2 molecules of hydrogen react with every molecule of oxygen to produce 2 molecules of water 2 moles of hydrogen react with every mole of oxygen to produce 2 moles of water. 2 H 2 + O 2 2 H 2 O. Multiply by 2 - PowerPoint PPT PresentationTRANSCRIPT
Stoichiometry
Element Measure
2 H2 + O2 2 H2O
2 molecules of hydrogen react with every molecule of oxygen to produce 2 molecules of water
2 moles of hydrogen react with every mole of oxygen to produce 2 moles of water
2 H2 + O2 2 H2O
Multiply by 24 H2 + 2 O2 4 H2O
4 moles of hydrogen react with every 2 moles of oxygen to produce 4 moles of water
Divide by 2 H2 + 0.5 O2 H2O
1 mole of hydrogen reacts with every 0.5 moles of oxygen to produce 1 mole of water
Pancake comparison
250 mL of pancake batter + 500 mL milk
6
How much pancake batter do I need if I only want to make 2 pancakes?
2 H2 + O2 2 H2O
How many moles of H2 are required to produce 4 moles of H2O?
How many moles of O2 are required?4 = 2xx = 4/2
x = 2 moles O2
2 H2 + O2 2 H2O
How many moles of O2 are required to produce 0.5 moles of H2O?
0.25 moles of O2
2 H2 + O2 2 H2O
How many moles of O2 are required to produce 7 moles of H2O?
3.5 moles of O2
2 H2 + O2 2 H2O
What mass of O2 and H2 are required to produce 9 moles of H2O?
n = mMM
m
MMn144 g of O2
2 H2 + O2 2 H2O
What mass of O2 and H2 are required to produce 9 moles of H2O?
2 1 2
94.5
18.18 g of H2
2 H2 + O2 2 H2O
What mass of H20 is present when 9 moles are produced?
2 1 2
99 4.5
162.18 g of H2O
2 H2 + O2 2 H2O
4 g of H2 react with what mass of O2 in the above reaction?
2 H2 + O2 2 H2O
4 g of H2 react with what mass of O2 in the above reaction?
2 1 2
31.68 g of O2
C3H8 + 5 O2 3 CO2 + 4 H2O
220 g of C3H8 react in the above reaction. What mass of H2O is produced?
C3H8 + 5 O2 3 CO2 + 4 H2O
220 g of C3H8 react in the above reaction. What mass of H2O is produced?
1 5 3 4
Pb(NO3)2 + 2 NaI PbI2 + 2 NaNO3
50 mL of a 0.5 mol/L solution of NaI reacts to produce how many grams of PbI2?
C = nV
Pb(NO3)2 + 2 NaI PbI2 + 2 NaNO3
50 mL of a 0.5 mol/L solution of NaI reacts to produce how many grams of PbI2?
1 2 1 2
Stoichiometry Steps
1. Write and balance the equation2. Write the ratio of substances in moles on top of the
equation3. Convert the given information into moles
(if necessary)4. Complete a cross-multiplication to determine the
number of moles of the substance in question5. Convert the answer into the required units (e.g.
grams)6. Write out the answer to the question in correct units.