Chemistry Reference
In-Depth Information
isolating this unknown, and a review of algebra would be important for
these students. If volume is the unknown, you isolate it by multiplying both
sides of the original equation by volume, and then dividing both sides of
the equation by density, as shown here.
Isolating Volume in the Density Formula
mass
volume
Density =
Original Fomula:
mass
volume
Step 1. Multiply both sides by volume:
volume × density =
× volume
volume × density = mass
volume × density
density
mass
density
Step 2. Divide both sides by density:
=
This gives us our working formula
for solving for volume:
mass
density
m
D
volume =
or V =
Now, let's try an example where the volume is the unknown.
Example 3
How much space would a 2.75 g sample of a substance occupy, if it
has a density of 0.993 g/cm
3
?
Given: m = 2.75 g
D = 0.993 g/cm
3
Find:
volume
m
D
2.75 g
0.993 g/cm
3
= 2.7693857 cm
3
v =
=
which rounds to 2.77 cm
3
Try the following practice questions and check your answers at the end
of the chapter before moving on to the next lesson.
Lesson 2-6 Review
1.
What is the density of an object with a mass of 2.34 g and a volume of
7.3 cm
3
?
2.
Calculate the mass of a 0.50 cm
3
-sized sample of a material with a
density of 5.5 g/cm
3
.
3.
What is the mass of a 1.29 cm
3
sample of a material with a density of
32.7 g/cm
3
?
