Question

Volume occupied at pressure of 760 mm of Hg is 500cm³ . What is the pressure of gas, if gas occupies half of its original volume? The temperature is kept constant.

Answer 1

At constant temperature, the product of pressure and volume is constant (Boyle's law).  Use that to find the new volume.

 

P1V1 = P2V2

 

V2 = P1V1/P2 = (760 mm Hg)(500 ml) / (380 mm Hg) = 1000 ml