To determine the amount of heat energy required to change water at 100 degrees Celsius to steam at 100 degrees Celsius, we need to consider the different phases and the associated heat transfer involved. Here's the breakdown:
- Heating water from 100 degrees Celsius to its boiling point: The specific heat capacity of water is approximately 4.186 J/g°C. To heat 0.50 kg (500 g) of water from 100°C to its boiling point at 100°C, we use the formula:
Q = m * c * ΔT
Where: Q = heat energy m = mass of the substance (water) = 500 g c = specific heat capacity of water = 4.186 J/g°C ΔT = change in temperature = (100°C - 100°C) = 0°C
Plugging in the values, we get: Q = 500 g * 4.186 J/g°C * 0°C Q = 0 J
No heat energy is required to change the water's temperature from 100°C to its boiling point because the temperature remains constant during the phase change.
- Phase change from water to steam (vaporization): To calculate the heat energy required for vaporization, we use the formula:
Q = m * L
Where: Q = heat energy m = mass of the substance (water) = 500 g L = latent heat of vaporization of water = 2260 J/g
Plugging in the values, we get: Q = 500 g * 2260 J/g Q = 1,130,000 J
Therefore, the heat energy needed to change 0.50 kg of water at 100 degrees Celsius to steam at 100 degrees Celsius is 1,130,000 joules (or 1.13 megajoules).