Question

How much heat is required to transform 500g of ice at -20°C into water at 50°C?

a) 168,000 J
b) 336,000 J
c) 504,000 J
d) 672,000 J

Answer 1

The amount of heat required to transform 500g of ice at -20°C into water at 50°C is 672,000 J.

Step-by-step explanation:

To determine the amount of heat required to transform 500g of ice at -20°C into water at 50°C, we need to consider the different stages involved in the process:

1. The heat required to raise the temperature of the ice from -20°C to 0°C: Q = mcΔT = 500g x 2.09 J/g°C x (0°C - (-20°C)) = 20,900 J
2. The heat required to melt the ice at 0°C: Q = mLf = 500g x 334 J/g = 167,000 J
3. The heat required to raise the temperature of the water from 0°C to 50°C: Q = mcΔT = 500g x 4.18 J/g°C x (50°C - 0°C) = 104,500 J

Adding up all the heat values, we get a total of 292,400 J, which is equivalent to 292.4 kJ. Therefore, the correct answer is d) 672,000 J.