Water and heat the water to 50 C7

6) How much energy would it take to heat 40g of water from 80C to 100C. turni

steam, and then heat the steam from 100C to 180C?

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