Answer:
When the 5 g sample of water is cooled from 12°C to -7°C, approximately -394.1 J of heat is released. Note that the negative sign indicates heat being released, as the water is cooling down.
Step-by-step explanation:
To calculate the amount of heat released when a sample of water is cooled, we can use the formula:
Q = mcΔT
Where:
Q represents the amount of heat released,
m is the mass of the water (in grams),
c is the specific heat capacity of water (which is 4.18 J/g°C),
and ΔT is the change in temperature (final temperature - initial temperature).
In this case, we have a 5 g sample of water that is cooled from 12°C to -7°C.
Let's calculate the amount of heat released step by step:
1. Calculate the change in temperature:
ΔT = (-7°C) - (12°C)
ΔT = -19°C
2. Plug in the values into the formula:
Q = (5 g) * (4.18 J/g°C) * (-19°C)
3. Calculate the amount of heat released:
Q = -394.1 J