Everything Science Grade 11

CHAPTER 5. THERMAL PROPERTIES AND IDEAL GASES 5.3

gas occupies a greater volume than it did at thestart. We saw this in thefirst demonstration. Because
the glass bottle couldn’texpand, the gas pushedout the balloon instead.

Exercise 5 - 2

The table below givesthe temperature (in◦C) of a number of gases under different volumes at a
constant pressure.

Volume (�) He H 2 N 2 O

0 -272.4 -271.8 -275.0

0.25 -245.5 -192.4 -123.5

0.5 -218.6 -113.1 28.1

0.75 -191.8 -33.7 179.6

1.0 -164.9 45.7 331.1

1.5 -111.1 204.4 634.1

2 -57.4 363.1 937.2

2.5 -3.6 521.8 1240.2

3.0 50.2 680.6 1543.2

3.5 103.9 839.3 1846.2

1. On the same set of axes, draw graphs to showthe relationship betweentemperature and volume
   for each of the gases.


2. Describe the relationship you observe.


3. If you extrapolate the graphs (in other words, extend the graph lineeven though you may not
   have the exact data points), at what temperaturedo they intersect?


4. What is significant about this temperature?

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Example 3: Charles’s Law 1

QUESTION

Ammonium chloride and calcium hydroxide are allowed to react. Theammonia that is re-

leased in the reaction iscollected in a gas syringe and sealed in. This gas is allowed to come

to room temperature which is 32◦C. The volume of the ammonia is found to be122 ml. It

is now placed in a water bath set at 7◦C. What will be the volume reading after the syringe

has been left in the bathfor a some time (e.g. 1 hour) (assume the plunger moves completely

freely)?

SOLUTION

Step 1 : Write down all the information that you knowabout the gas.

V 1 = 122 ml and V 2 =? T 1 = 32◦C and T 2 = 7◦C