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: Thermal concepts questions (chem related)

  1. Jan 9, 2010 #1
    I know these aren't exactly physics problems but I'm being asked them in physics so...
    1. The problem statement, all variables and given/known data
    1) As lead melts there is a change in it's...
    Heat of fusion (what I now think it is)
    Avg molecular KE (what I thought it was)
    Avg molecular PE

    2)In a room there is 250kg of air, in the avg molecular mass of air is 28.8g/mol (.0288kg) how many particles of "air" is in the room?

    2. Relevant equations
    1) none

    2) n=m/M
    3. The attempt at a solution
    1) look above in parentheses

  2. jcsd
  3. Jan 9, 2010 #2


    User Avatar
    Homework Helper

    Your answers to #1 are wrong. Check your textbook for an explanation of the heat of fusion. I can explain it here, but it's too important a concept to cover thoroughly in one forum post.

    For #2, you found the number of moles. The question asks for the number of actual particles.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook