a freezer in a refrigerator takes 2 hrs to comvert 2.15kg of water initially at 21.5 degrees celsius to just frozen ice. calculate the rate at which the reezer absorbs heat.
rate= heat/time= (mcdeltat +m Hf)/time
26.8 J s-1
A freezer in a refrigerator takes 2.00 hours to convert 2.15 kg of water initially at 21.5 °C to just frozen ice. Calculate the rate at which the freezer absorbs heat.
To calculate the rate at which the freezer absorbs heat, we need to use the formula for heat transfer:
Q = mcΔT
Where:
Q is the amount of heat transferred
m is the mass of the substance (water in this case)
c is the specific heat capacity of the substance (for water, it is approximately 4.18 J/g°C)
ΔT is the change in temperature
First, we need to find the change in temperature of the water. The initial temperature is 21.5 degrees Celsius, and we know the water is being converted to ice, which occurs at 0 degrees Celsius. So the change in temperature is:
ΔT = final temperature - initial temperature
ΔT = 0°C - 21.5°C = -21.5°C
Next, we need to convert the mass of water from kilograms to grams:
mass = 2.15 kg * 1000 g/kg = 2150 g
Now we can calculate the amount of heat transferred:
Q = mcΔT
Q = 2150 g * 4.18 J/g°C * (-21.5°C)
Q ≈ -195,695 J
Since the freezer is absorbing heat, the value of Q will be negative.
Finally, we need to find the rate at which the freezer absorbs heat. We know that the process takes 2 hours, which is equivalent to 7200 seconds. So the rate of heat absorption is:
Rate = Q / t
Rate = -195,695 J / 7200 s
Calculating this value gives us the rate at which the freezer absorbs heat.