Term
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Definition
· Atoms are to small to mass in grams.
· 1 amu = 1.66 x 10-24g |
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Term
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Definition
the mass in grams of 1 mol of a substance. The molar
mass is obtained by summing the masses of the component atoms. |
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Term
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Definition
Is the same as molar mass but used to describe the mass in grams of 1 mol of a substance that is ionically bonded
together. |
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Term
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Definition
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Term
| Mass Fraction for a given compound |
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Definition
% Mass = (Part of Compound / Total Mass) x 100
Part = mass of the element present in 1 mol of compound.
Total Mass = Mass of 1 mol of the compound |
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Term
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Definition
Represents the relative numbers of the various
types of atoms present. |
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Term
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Definition
The formula of a compound that expresses the
smallest whole number ratio of the atoms present. |
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Term
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Definition
The actual formula of a compound, the one that
gives the composition of the molecules that are present. |
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Term
| Steps for Determining the Empirical Formula of a Compound |
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Definition
· Obtain the mass of each element present (in grams)
· Determine the number of moles of each type of atom present
· Divide the number of moles of each element by the smallest
number of moles to convert the smallest number to 1. If all of the
numbers so obtained are integers (whole numbers), these are the
subscripts in the empirical formula. If one or more of these
numbers are not integers, go on to step 4.
· Multiply the numbers you derived in step 3 by the smallest integer
that will convert all of them to whole numbers. This set of whole
numbers represents the subscripts in the empirical formula. |
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Term
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Definition
A molecular formula contains a whole number of empirical formula
units.
· Molecular formula = n x empirical formula
n = How many times greater the molecular formula ratio is
compared to the empirical formula ratio.
· n = Molar Mass / Empirical Formula Mass |
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