mole. stoichiometry the study of quantitative relationships between the amounts of reactants used...
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Mole
StoichiometryThe study of quantitative relationships between the
amounts of reactants used and products formed by a chemical reactions; it is based on the law
of conservation of mass.
MoleThe SI base unit used to
measure the amount of a substance.
Avogadro’s NumberThe number of representative particles in a mole, and can be
rounded to three significant digits:
6.02 X 1023 molecules/mol
moles/L =M
Molarity
Molecule Forms when two or
more atoms covalently bond.
To find the number of molecules it takes to equal a
certain number of moles. Take the number of moles given and
multiply by Avogadro’s number.
How many molecules of Sucrose is in 3.50 moles of Sucrose.
3.50 mol Sucrose X 6.02x1023 molecules/mol =2.11x1024molecules of Sucrose
How many molecules of Sodium Hydroxide is in 4.80 moles of
Sodium Hydroxide?4.80 mol Sodium Hydroxide X
6.02x1023molecules/mol
=2.89x1024 molecules of Sodium Hydroxide
To find the number of moles it takes to equal a certain
number of molecules. Take the number of molecules given and divide by Avogadro’s number.
How many moles of Sucrose is in 3.54x1024 molecules of
Sucrose.
3.54x1024 molecules of Sucrose ÷
6.02x1023 molecules/mol
=5.88 moles of Sucrose
How many moles of Sodium Hydroxide is in 5.63x1024
molecules of Sodium Hydroxide.
5.63x1024 molecules NaOH ÷6.02x1023 molecules/mol=9.35 moles of NaOH
Molar MassThe mass in grams of one mole of any pure
substance.g/mol
To find the number of grams of substance. Take the number of
moles given and multiply by the substance’s molar mass.
Find the mass of 3.2 moles of Butane needed to complete the
reaction.
3.2 mol of Butane X
58.14 g/mol
=186.05 g of Butane
Find the mass of 4.5 moles of Pentanol needed to complete
the reaction.
4.5 mol Pentanol X86.15 g/mol=387.68 g of Pentanol
To find the number of moles of substance. Take the number of grams given and divide by the
substance’s molar mass.
Find the moles of 23 g of water needed to complete the
reaction.
23 g water ÷18.02 g/mol=1.28 mol of water
Find the moles of 112 g of Hydrochloric Acid needed to
complete the reaction.
112 g of Hydrochloric Acid ÷36.46 g/mol=3.07 mol of Hydrochloric Acid
To find the number of moles of an element in a compound,
multiply the moles of the compound with the ratio of
number of elements to 1 mol of compound.
How many moles of Fluorine is found in 5.50 moles of Freon
(CCl2F2).
5.50 mol CCl2F2 X
2 mol F atoms/1 mol CCl2F2 = 11.0 mol F atoms
How many moles of Oxygen is found in 4.75 moles of Glucose
(C6H12O6).
4.75 mol C6H12O6 X 6 mol O atoms/1 mol C6H12O6 = 28.5 mol O atoms
To find the moles of a compound, take the mass of the compound and divide by
the molar mass of the compound.
How many moles are there of 47g of water?
47g of water ÷
18.02 g/mol of water
= 2.61 mol of water
How many moles are there of 21g of Benzene?
21g of Benzene ÷
78.12 g/mol of Benzene
= 0.27 mol of Benzene
Mole Ratio
In a balanced equation, the ration between the
numbers of moles of any two substances.
To find mole ratio, put moles of one substance over the moles of another substance in chemical
equation.2KClO3 → 2KCl + 3O2
2mol KClO3/2mol KCl
2 mol KClO3/3mol O2