Refer to the temperature versus time graph (Figure 2) when answering the questions in Parts C through F. A system consists of 250 g of water. The system, originally at T _A = 21.0 ?C, is placed in a freezer, where energy is removed from it in the form of heat at a constant rate. The figure shows how the temperature of the system takes t ₁ = 10 min = 600 s to drop to 0? C, after which the water freezes. Once the freezing is complete, the temperature of the resulting ice continues to drop, reaching temperature T _B after an hour. The following specific heat and latent heat values for water may be helpful.

How much energy must be transferred out of the system as heat Q to lower its temperature to 0?C?

ANSWER Q = 2.20 x 10^4

Cooling Power of P is 36.6 W

At what time t 2 will the water be completely frozen so the temperature can begin to fall below 0?C?

(seconds)

Transcribed Image Text:

specific heat of ice (at 0°C) latent heat of fusion (ice to water phase change at 0°C) specific heat of water (at 15°C) latent heat of vaporization (water to steam phase change at 100° C) specific heat of steam (at 110° C) G = 2.10 J/(g.K) Lf = 333.7 J/g Cw = 4.186 J/(g.K) Lv = 2256 J/g Cs = 2.01 J/(g.K) specific heat of ice (at 0°C) latent heat of fusion (ice to water phase change at 0°C) specific heat of water (at 15°C) latent heat of vaporization (water to steam phase change at 100° C) specific heat of steam (at 110° C) G = 2.10 J/(g.K) Lf = 333.7 J/g Cw = 4.186 J/(g.K) Lv = 2256 J/g Cs = 2.01 J/(g.K)

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Mass of water m 025 kg Temperature TA 21C TB ... View the full answer