Answer:
9.4×10⁴J
Explanation:
The specific heat capacity (SHC) of water, which is the amount of energy (J) that it takes to warm 1mL (1mL = 1g) of water by 1°C is 4.184 J/g×°C.
Q = mcΔT relates energy to mass, SHC, and change in temperature.
The mass of water is 300g, and will not change because no water will evaporate until it reaches 100°C.
The change in temperature is 75°C:
100°C - 25°C = 75°C
(Desired temp. - initial temp. = change in temp.)
Subbing these values into Q=mcΔT:
Q = 300g × 4.184J/g×°C × 75°C
Q = 94140J
Scientific notation tells us that we have two significant figures, so:
Q = 9.4 × 10⁴J
