Chemistry Reference
In-Depth Information
This gives us:
V
1
P
1
T
2
T
1
V
2
P
2
=
Now we have the working formula necessary to solve the problem.
Given: V
1
= 4.85 L; P
1
= 101.8 kPa; T
1
= 314 K; V
2
= 2.00 L;
T
2
= 294 K
Find:
P
2
V
1
P
1
T
2
T
1
V
2
(4.85 L)(101.8 kPa)(294 K)
(314 K)(2.00 L)
P
2
=
=
= 231 kPa
Formula:
For our final example, let's try a problem where T
2
is the unknown.
Example 3
A sample of argon has a volume of 4.21 L at 34.0
o
C and 1.13 atm.
If the pressure is allowed to decrease to 1.00 atm, at what
temperature will this gas occupy 5.00 L?
As always, we will start by changing the temperature to the Kelvin scale,
by adding 273. Then we will list the given information and what we are
asked to find.
A sample of argon has a volume of 4.21 L at 34.0
o
C 307 K and
1.13 atm. If the pressure is allowed to decrease to 1.00 atm, at what
temperature will this gas occupy 5.00 L?
Given: V
1
= 4.21 L; T
1
= 307 K; P
1
= 1.13 atm; V
2
= 5.00 L;
P
2
= 1.00 atm
Find:
T
2
Now, let's isolate the unknown in the equation.
V
1
P
1
T
2
P
2
T
1
Original formula:
V
2
=
V
1
P
1
T
2
P
2
T
1
Multiply both sides by P
2
T
1
:
V
2
P
2
T
1
=
× P
2
T
1
V
2
P
2
T
1
V
1
P
1
T
2
=
V
2
P
2
T
1
V
1
P
1
T
2
V
1
P
1
=
Now, divide both sides by V
1
P
1
:
Our formula becomes:
V
1
P
1
