Final answer:
To heat one cup of water (250g) from 20°C to 100°C, the amount of energy needed is calculated using the specific heat capacity of water, resulting in 83,680 Joules.
Step-by-step explanation:
To determine how much energy it takes to heat one cup of water (250g) from 20°C to 100°C, we use the concept of specific heat capacity. The specific heat capacity of water is 4.184 J/g°C. Hence, the amount of energy required can be calculated by multiplying the mass of the water with the specific heat capacity and the change in temperature (ΔT).
Using the formula:
Q = m • c • ΔT
Where:
- Q = Heat energy (in joules)
- m = Mass of the water (in grams)
- c = Specific heat capacity of water (in J/g°C)
- ΔT = Change in temperature (in °C)
Substituting the given values:
Q = 250g • 4.184 J/g°C • (100°C - 20°C)
Q = 250g • 4.184 J/g°C • 80°C
Q = 250g • 334.72 J/°C
Q = 83680 Joules
Therefore, it takes 83,680 Joules to heat one cup of water from 20°C to 100°C without boiling it.