How much energy is released when 20.0 g of water is cooled from 50°C to 30°C (Cwater = 4.18 J / g*°C)

1672 J

Explanation:

We are supposed to find out the energy released by water when cooled from 50° C to 30°C.

We have the relation that,

H=msΔT

Information is given that s=4.18 J / g*°C,

m=20.0 g,

and ΔT is - 20° C.

Hence by substituting we get,

H=-20*20*4.18

(minus symbol represents that energy is being released)

1672 J is release when water is cooled from 50° C to 30°C.