Answer:
1672 J
Step-by-step 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 .