What pressure must be applied to a given sample of a gas in order to compress it to three- fourth of its original volume ?

Answer

`4//3` time the original pressure

Explanation

`P_(1) = P` bar , `P_(2) = ?`
`V_(1) = VL` , `V_(2) = 3//4 VL`
Since temperature is constant, Boyles' Law is applicable.
`P_(1)V_(1) = P_(2)V_(2)` or `P_(2) = (P_(1)V_(1))/(V_(2)) = ((P "bar") xx (VL))/((3//4 VL))`
`:. P_(2) - 4/3 P` bar i.e. `4//3` time the original pressures