If a certain gas occupies a volume of 10 l when the applied pressure is 5.0 atm , find the pressure when the gas occupies a volume of 2.5 l .

We assume the change in volume occurs at constant temperature and so we  use the Boyle's law formula .

We are given the initial volume and pressure as well as as final volume, the question wants the final pressure

So we make the subject of the formula

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.