Question

How much heat energy is released when 5 gm of water at 20 degree centigrade changes into ice at 0 degree take specific heat capacity of water as 4.2 joules per gram per kelvin specific latent heat of fusion of ice is 336 joules per gram

Answer 1

q1=mst. 20 to 0 degrees. q2=ml. 0 water to 0 ice degree. Q=q1+q2 ; q1= 5×4.2×20=420j and. q2= 5×336 =1680j thereforemail Q=2100j

Answer 2

Q1=5×40×4.2

=840J

Q2=5×336

=1680J

Q1+Q2=840+1680

= 2520J