Answer:
6.93 kg
Explanation:
m1 = 8.90 kg
T1 = -5°C
m2 = 12 kg
T2 = 15°C
constant needed:
c (ice) = 2100 J/kg °C
c (water) = 4200 J/kg °C
L (Latent Heat) = 336 000 J/kg
Black Principle
Q (release) = Q (absorbs)
Q (release) max = m2 c(water) ∆T2
Q (release) max = 12 x 4200 x (15-0)
Q (release) max = 756 000 J
Q (absorbs) = m1 c(ice) ∆T1 + m1 L
Q (absorbs) = 8.9 x 2100 x (0-(-5)) + 8.9 x 336 000
Q (absorbs) = 93 450 + 2 990 400 = 3 083 850 J
since Q (absorbs) is much much bigger than Q (release), only a few litlle ice melting. So we need to see how much ice melting and how many left.
Q (release) - Q (absorbs) ice -5°C to ice 0°C = 756000 - 93450 = 662550
mass of melting Ice
Q (absorbs) melting ice = m(melting) L
662 550 = m(melting x 336 000
m (melting) = 662 500/336 000
m (melting) = 1.977 kg
so the ice remains is 8.90 - 1.97 = 6.93 kg
