Enthalpy change of atomisation

• Diehard_89

  29 Jul 07, 22:07

  we normally learn atoms one right
  
  how about atomisation of compounds?
  
  how to write the reaction for the enthalpy change of atomisation of compound like C6H5N?
• deathscythe99

  29 Jul 07, 22:11

  Originally posted by Diehard_89:

  we normally learn atoms one right
  
  how about atomisation of compounds?
  
  how to write the reaction for the enthalpy change of atomisation of compound like C6H5N?

  Enthalpy change of atomisation? Got this meh?
• Diehard_89

  29 Jul 07, 22:12

  got
  
  are you in jc?
  
  I think secondary school never learn
• unclebutcher

  29 Jul 07, 22:16

  definition
  
  This is the enthalpy change when 1 mole of a substance is converted to gaseous atoms under standard conditions.(25 C 1 atm)
  
  so just -organic substance-(s) -organic substance (g)
  
  also, cl2(g) 2cl(s)
  
  or I2(s) 2I(g)
• Diehard_89

  29 Jul 07, 22:17

  Originally posted by unclebutcher:

  definition
  
  This is the enthalpy change when 1 mole of a substance is converted to gaseous atoms under standard conditions.(25 C 1 atm)
  
  so just -organic substance-(s) -organic substance (g)
  
  also, cl2(g) 2cl(s)
  
  or I2(s) 2I(g)

  I thought should be the other way round?
  
  1 mole of atoms formed from its consituent element..that's what my note mentioned
• unclebutcher

  29 Jul 07, 22:19

  The standard enthalpy change of atomisation of a compound, symbol delta H atm(with the circle with line thru it), is the enthalpy increase that takes place when one mole of the compound in the defined physical state, is broken down into gas atoms under standard conditions.
  
  so c6h5n(s) 6C(g) + 5H(g) + N(g)[/b]
• unclebutcher

  29 Jul 07, 22:20

  Originally posted by Diehard_89:

  I thought should be the other way round?
  
  1 mole of atoms formed from its consituent element..that's what my note mentioned

  no. its one mole of substance forming products. one mole of reactants, not products. u wat jc???? i think ur notes typo
• Diehard_89

  29 Jul 07, 22:21

  ohh so for compound is like that arh
  
  thanks thanks
  
  where do you get that definition from?
  
  I didn't learn before
• Diehard_89

  29 Jul 07, 22:22

  typo meh?
  
  but when question comes we always take the products to be 1 mole one
  
  I am from Anderson
• unclebutcher

  29 Jul 07, 22:22

  Originally posted by Diehard_89:

  ohh so for compound is like that arh
  
  thanks thanks
  
  where do you get that definition from?
  
  I didn't learn before

  from notes................ =.=
• unclebutcher

  29 Jul 07, 22:23

  Originally posted by Diehard_89:

  typo meh?
  
  but when question comes we always take the products to be 1 mole one
  
  I am from Anderson

  i think atm is the exception...u shud be j2 right? maybe u forgot...
• Diehard_89

  29 Jul 07, 22:23

  Originally posted by unclebutcher:

  from notes................ =.=

  
  
  different eras so reduced content I think
• unclebutcher

  29 Jul 07, 22:23

  Originally posted by Diehard_89:

  
  
  different eras so reduced content I think

  erm i'm j1 now
• Diehard_89

  29 Jul 07, 22:23

  Originally posted by unclebutcher:

  i think atm is the exception...u shud be j2 right? maybe u forgot...

  haha ok maybe lor
  
  thanks
  
  shall clarify with my tutor
  
  yeap J2
• Diehard_89

  29 Jul 07, 22:24

  Originally posted by unclebutcher:

  erm i'm j1 now

  
  
  what's your school
  
  got learn atomisation of compound arh
• unclebutcher

  29 Jul 07, 22:25

  Originally posted by Diehard_89:

  
  
  what's your school
  
  got learn atomisation of compound arh

  catholic
  
  i just learnt enthalpy b4 june hols
• unclebutcher

  29 Jul 07, 22:25

  i nvr learn enthalpy of cmpd but derive from definition ma
• deathscythe99

  29 Jul 07, 22:31

  Originally posted by Diehard_89:

  got
  
  are you in jc?
  
  I think secondary school never learn

  I forgot
• teraexa

  30 Jul 07, 12:14

  Enthalpy change of atomisation is the amount of energy change when the substance in its respective state under standard conditions (ie 298K and 1 atm) is converted into 1 mole of gaseous atoms.
  
  Anyway where got so guai lan question one? Asking enthalpy change of atomisation for an organic compound... I have never met that before, not in H2 Chem, not in H3 Chem and not even in Chem Olympiad. Hmmm this is interesting.