Question

Suppose you have 600.0 grams of room temperature water (20.0 degrees Celsius) in a thermos. You drop 90.0 grams of ice at 0.00 degrees Celsius into the thermos and shut the lid.(a) What is the equilibrium temperature of the system?(b) How much ice is left (in grams)?

Answer 1

Explanation:

a) Heat is the power flowing from elevated to low temperatures. So the ice gains the heat that was lost by the water.

Thus, heat lost = mcΔT

= 600 × 2 (20.0 degrees Celsius)

= 12000 cal

The heat gained by the ice = m  ×  L

= 90 × 80

= 7200Cal

b) Since, the heat that the water lost is equal to the ice latent freezing heat of the ice. Thus,

12000cal =1 × 80Cal/gm

m1 = 150gm.

Thus, the mass of the ice that remains -

150-150

= 0gm