« previous next »
Pages: [1]   Go Down

Author Topic: chemistry:enthalpy changes !!!!!!  (Read 785 times)

Offline ruby92

  • SF Citizen
  • ***
  • Posts: 208
  • Reputation: 258
chemistry:enthalpy changes !!!!!!
« on: March 17, 2010, 02:47:36 pm »
the chief gas in bio gas is methane
(a)the standard enthalphy change of formation deltaHf (CH4) cannot be measured directly.
i calculate the standard enthalpy change of formation of methane from the deltaHc values below
     substance        deltaHc
CH4                          -890
C                             -393.5
H2                            -285.9

ii suggest why the enthalpy change of formation of methane cannot be measured directly?
« Last Edit: March 17, 2010, 03:47:39 pm by ruby92 »
Logged

Offline Saladin

  • The Samurai
  • Honorary Member
  • SF V.I.P
  • *****
  • Posts: 6530
  • Reputation: 59719
  • Gender: Male
  • I believe in those who believe in me
    • Student Tech
Re: chemistry:enthalpy changes !!!!!!
« Reply #1 on: March 18, 2010, 04:47:37 am »
There u go.
Logged

Offline ruby92

  • SF Citizen
  • ***
  • Posts: 208
  • Reputation: 258
Re: chemistry:enthalpy changes !!!!!!
« Reply #2 on: March 18, 2010, 03:32:07 pm »
thnk u so muchhh :D
Logged
Pages: [1]   Go Up
« previous next »