Gas Laws

SAMPLE PROBLEM 2
A container of oxygen has a volume of 349 mL at a temperature
of 22°C. What volume will the gas occupy at 50.°C?
SOLUTION
1. ANALYZE
• What is given in the the original volume and temperaproblem?
ture of the oxygen sample, and the
new temperature of the sample
• What are you asked to find? the volume at the new temperature
Items Data
Original volume, V 1
Original temperature, t 1
Original Kelvin temperature, T 1
New volume, V 2
New temperature, t 2
New Kelvin temperature, T 2
2. PLAN
• What steps are needed to Rearrange the Charles’s law equacalculate
the new volume tion to solve for V 2, substitute
of the gas? known quantities, and calculate.
V 1
T 1
122 Chapter 11
1
V2 T2 349 mL O 2
22°C
(22 273) K 295 K
? mL O 2
50.°C
to solve for V2 ,
multiply both sides of
the equation by T2 to
isolate V2 insert data and solve for V2 (50. 273) K 323 K
V 1 T 2
T 1
2
V 2
3. COMPUTE
Substitute data for the terms of the equation, and compute the result.
V 2 V 1T 2
T 1
349 mL O 2 323 K
295 K
382 mL O 2
4. EVALUATE
• Are the units correct? Yes; units canceled to give mL O2. • Is the number of significant Yes; the number of significant figfigures
correct? ures is correct because data were
given to three significant figures.
• Is the answer reasonable? Yes; the temperature increased, so
the volume must also increase.