Answer:
107,200J or 25.62 kcal
Explanation:
The latent heat of water is 4.2J/g °C so the energy needed to increase the tempearture from 80 °C to 100°C will be:
40g * 4.2J/g °C * (100-80°C )= 3,360J
The heat of vaporization of water is 2260J/g so the energy need to change water from liquid to gas is:
40g * 2260J/g = 90,400J
The heat needed to increase steam temperature should be same as latent heat of water, 4.2J/g °C . So, the energy needed to increase temeprature from 100 to 180 will be:
40g * 4.2J/g °C * (180-100°C )= 13,440J
The total energy needed will be: 3,360J + 90,400J +13,440J= 107,200J
