Conversion Factors
In chemistry, it is often useful
to be able to convert from one
unit of measure to another
For example:
mass of a substance converted to the
number of atoms in that substance,
or converting from one metric unit
to another metric unit
First we will see how it works with dozen.
You know that a dozen is 12 of something.
If you have 36 donuts,
how many dozen donuts do you have?
You want to know how many dozen in 36 donuts,
and you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
12 donuts
individual donuts to dozen donuts:
In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
12 donuts
individual donuts to dozen donuts:
36 donuts x
1 dozen
12 donuts
In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
12 donuts
individual donuts to dozen donuts:
36 donuts x
1 dozen
12 donuts
= 36 donuts x 1 dozen
12 donuts
In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
12 donuts
individual donuts to dozen donuts:
36 donuts x
1 dozen
12 donuts
= 36 donuts x 1 dozen
12 donuts
= 36 dozen
12
In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
12 donuts
individual donuts to dozen donuts:
36 donuts x
1 dozen
12 donuts
= 36 donuts x 1 dozen
12 donuts
= 36 dozen
12
=
3 dozen
In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
12 donuts
individual donuts to dozen donuts:
36 donuts x
1 dozen
12 donuts
= 36 donuts x 1 dozen
12 donuts
= 36 dozen
12
=
3 dozen
If you have 2.5 dozen donuts, how many individual
donuts are there?
there are 12 donuts
2.5 dozen x 12 donuts
1 dozen
in 1 dozen
If you have 2.5 dozen donuts, how many individual
donuts are there?
2.5 dozen x 12 donuts = 2.5 dozen x 12 donuts
1 dozen
1 dozen
2.5
x
12
donuts
=
1
= 30 donuts
Let’s try converting donut mass to
number of donuts…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
What is the relationship between grams and donuts?
150 grams = 1 donut
150 g = 1 donut
150 g
=1
1 donut
these are your
conversion factors
1 donut
=
1
150 g
150 g = 1 donut
150 g
=1
1 donut
converts donuts to
grams (grams on top)
1 donut
=
1
150 g
150 g = 1 donut
150 g
=1
1 donut
converts grams to
donuts (donuts on top)
1 donut
=
1
150 g
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
9900 grams
begin with the amount
given in the problem
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
grams
if each donut has a mass of 150 grams?
1
donut
1
donut
9900grams
grams xx
9900
150
grams
150
g
converts grams
to donuts
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
1
donut
9900 grams x
150 grams
=
9900 g x 1 donut
150 g
9900
donuts
=
150
= 66 donuts