1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Energy Required to Change Water into Steam

  1. Jul 20, 2011 #1
    1. The problem statement, all variables and given/known data

    How much energy is required to change one-quarter of 8.0kg of water at 25 C into steam?

    The way I see it, the entirety of the 8.0kg of water must be brought from 25 C to 100 C, then only 2.0kg is changed to steam so...

    Specific heat capacity (of water) = 4200 J / kg C
    Latent heat of vaporization (of water) = 2.3 * 10^6 J/kg

    Q total = (8.0kg) (4200 J / kg C) (100-25) + (2.0kg) (2.3 * 10^6 J/kg)
    Q total = 7.12 * 10^6 J

    I'm not 100% sure if I'm doing this properly. Does this look correct?
  2. jcsd
  3. Jul 20, 2011 #2
    That looks correct to me!
  4. Jul 20, 2011 #3
    Cool, thanks!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook