A small bubble rises from the bottom of a lake, where the temperature and pressure are `8^(@) C` and `6.4 atm` , to the surface of the water , where the temperature is `25^(@) C` and pressure is `1.0 atm`. Calculate the final volume `("in mL")` of the bubble if its initial volume was `2.1 mL`.
Strategy : The amount of gas in the bubble remains constant `(n_(1) = n_(2))` but there is a change in all the three quantities `p , V`, and `T`. This suggests that we use the combined gas law. We tabulate what is known and what is asked for , solve the combined gas law for the unknown quantity `V_(2)` and substitute the known values.

Explanation

`{:("Initial conditions",,,,Fi nal conditions ),(p_(1) = 6.4 atm,,,,p_(2) = 1.0 atm), (V_(1) = 2.1 mL,,,,V_(2) = ?),( T_(1) = (8 + 273)K,,,,T_(2) = (25 + 273)K):}`
`= 298 K`
To calculate the final volume `(V_(2))` , we rearrange Eq.(5.20) as follows:
`V_(2) = (p_(1) V_(1) T_(2))/(p_(2) T_(2)) = ((6.4 "atm")(2.1 mL) (298 K))/((1.0 atm) (281 K))`
`= 14 mL`