How much heat is released by a 15-gram sample of water when it is cooled from 40.oC to 30.oC?

Q = -627.6 J

Explanation:

Mass, m = 15 grams

Initial temperature,

Final temperature,

We need to find the amount of heat released by this much of sample of water. We know that heat released is given by the below formula :

c is specific heat of water,

So,

Hence, 627.6 J of heat is released and negative sign shows that energy is being given off.

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.