Advertisements
Advertisements
Question
Give its
(i) graphical representation,
(ii) mathematical expression
(iii) significance
Advertisements
Solution
(i) Graphical representation of Charles's law
T vs V: The relationship between the volume and the temperature of a gas can be plotted on a graph. A straight line is obtained.

(ii) Mathematical expression
Let V0 be the volume of a fixed mass of a gas at 0 °C, and let V be its volume at temperature t °C at, constant pressure. then, according to Charles Law
`"V" = "V"_0 + "V"_0/273 t` (when P is constant)
`"V" = "V"_0 (1 + t/273) = "V"_0 ((273 + t)/273)` .......(1)
`"V" = "V"_0/273 "T" "where" "T" = 273 + "t"`
For a given mass of a gas,
`"V"_0/273 = "constant"`
`"V" = "k" xx "T"` (where k is constant)
(iii) Significance of Charles's Law: The volume of a given mass of a gas is directly proportional to its temperature; hence, the density decreases with temperature. This is the reason that
(a) Hot air is filled in balloons used for meteorological purposes. (b) Cable wires contract in winters and expand in summers.
APPEARS IN
RELATED QUESTIONS
Explain Charles's law on the basis of the kinetic theory of matter.
State the law which is represented by the following graph:

How did Charles's law lead to the concept of an absolute scale of temperature?
State the following:
Ice point in absolute temperature
Choose the correct answer:
The volume-temperature relationship is given by
2 liters of gas is enclosed in a vessel at a pressure of 760 mmHg. If the temperature remains constant, calculate pressure when volume changes to 4 dm3.
Calculate the final volume of a gas 'X' if the original pressure of the gas at STP is doubled and its temperature is increased three times.
It is found that on heating a gas its volume increases by 50% and its pressure decreases to 60% of its original value. If the original temperature was −15°C, find the temperature to which it was heated.
An LPG cylinder can withstand a pressure of 14.9 atmospheres. The pressure gauge of the cylinder indicates 12 atmospheres at 27°C. Because of a sudden fire in the building, the temperature rises. At what temperature will the cylinder explode?
It is required to reduce the volume of a gas by 20% by compressing it at a constant pressure. To do so, the gas has to be cooled. If the gas attains a final temperature of 157°C, find the initial temperature of the gas.
