Final answer:
To calculate the energy required to heat 18 g of water from 70°C to 100°C, you multiply the mass of the water by the specific heat capacity of water and by the change in temperature. Using the formula Q = m × c × ΔT with the values given, the result is 2,255.04 J.
Step-by-step explanation:
The student has asked to solve for the energy needed to heat 18 g of water from 70°C to 100°C. The specific heat of water is a crucial factor for this calculation. The specific heat is the amount of energy required to raise the temperature of a substance by a certain amount. In this case, it is the energy needed to heat water, which has a specific heat of 4.184 J/g °C.
To calculate the energy required, we use the formula Q = m × c × ΔT, where Q is the heat energy, m is the mass of the water, c is the specific heat capacity of water, and ΔT is the change in temperature. We are given that the mass of the water (m) is 18 g, the specific heat capacity of water (c) is 4.184 J/g °C, and the change in temperature (ΔT) from 70°C to 100°C is 30°C.
Plugging the values into the formula gives us: Q = 18 g x 4.184 J/g °C x 30°C. Multiplying these together, we find that the energy required to heat the water is 2,255.04 J.