A balloon full of air has a volume of 2.75 L at a temperature of 255 K. What is the balloon's volume at 318 K?

The relationship between the temperature and volume of a gas is described by Charles's Law:

                                    `~V_1/T_1` = `~V_2/T_2`

  `~V_1` = initial volume of the gas

  `~T_1` = initial temperature of the gas

  `~V_2` = final volume of the gas

  `~T_2` = final temperature of the gas

(Assume that the pressure and number of moles remain constant.)

There is an direct relationship between the temperature and volume of a gas. When the temperature of a gas increases, the volume also increases. The reverse is also true - when the temperature of a gas decreases, the volume also decreases.

According to the problem,

  `~V_1` = 2.75 L

  `~T_1` = 255 K

  `~V_2 ` = ? L

  `~T_2` = 318 K

Step 1: Rearrange the formula for Charles's Law to isolate `~V_2` .

   `~V_2` = `~V_1T_2`  `-:`  `~T_1` ` `

Step 2: Plug in the given values and calculate.

   `~V_2` = [(2.75 L)(318 K)]/255 K = 3.43 L