The pressure on 40ml of a gas is increased from 760mm to 800mm. find the new volumes at the same temperature.

The new volume is 38 ml.

Explanation:

At NTP,

P1  = 760 mm,

P2 = 800 mm,

V1 = 40 ml

Boyle's law states that when a gas is held at a constant temperature and mass in a closed container, the volume and pressure vary inversely.

By applying Boyle's law,

                       P1  V 1  = P2  V2

where P1, P2 represents the pressure of a gas,

           V1, V2 represents the volume of a gas.

                        P1  V 1  = P2  V2

             760×40 = 800×V  2

                          V 2   =  (760×40)  / 800

                           V2  = 38 mL.