Q = 2,000 * 4.18 * 80= 668,800 Joules
The equation you mentioned is the formula for calculating the amount of heat required to change the temperature of a substance. Let's break it down:
Q represents the amount of heat energy needed, measured in Joules.
m represents the mass of the substance, measured in grams.
c represents the specific heat capacity of the substance, which is a measure of how much heat energy is needed to raise the temperature of 1 gram of the substance by 1 degree Celsius. Specific heat is measured in Joules per gram per degree Celsius.
Δt represents the change in temperature, measured in degrees Celsius.
So, in this case, we have:
m = 2,000 grams (the mass of the water)
c = 4.18 J/g°C (the specific heat of water)
Δt = 80°C (the change in temperature needed to bring the water up to boiling)
Plugging these values into the formula, we get:
Q = m * c * Δt
Q = 2,000 * 4.18 * 80
Q = 668,800 Joules
Therefore, to bring 2 liters of water up to boiling point, we need to absorb 668,800 Joules of heat energy.