Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    5
    ReputationRep:
    What is the enthalpy of atomisation of SiH4? I'm not asking for the value, I'm asking how does atomisation relate to SiH4?

    The definition of atomisation: When mole of gaseous ATOMS are formed from its CONSTITUENT elements.

    e.g. Na(s) to Na(g)

    But the "enthalpy of atomisation of SiH4" does not abide by the definition. First of all, it's a molecule and not an atom. Secondly, if we atomise SiH4 what will its constituent elements be? It can't be Si and H2 as we are atomising FROM SiH4.

    Really confused :| any help would be appreciated!


    Posted from TSR Mobile
    • Community Assistant
    • Study Helper
    Offline

    17
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by ps1265A)
    What is the enthalpy of atomisation of SiH4? I'm not asking for the value, I'm asking how does atomisation relate to SiH4?

    The definition of atomisation: When mole of gaseous ATOMS are formed from its CONSTITUENT elements.

    e.g. Na(s) to Na(g)

    But the "enthalpy of atomisation of SiH4" does not abide by the definition. First of all, it's a molecule and not an atom. Secondly, if we atomise SiH4 what will its constituent elements be? It can't be Si and H2 as we are atomising FROM SiH4.

    Really confused :| any help would be appreciated!


    Posted from TSR Mobile

    Atomisation means turning into gaseous atoms. You are correct in that it does not fit the context in which you have been given the definition.

    However, that's the beauty of thermodynamics - you can define things as you wish and even if it is not possible to actually carry out the process, you can still calculate a value.

    If you wish to turn SiH4 into gaseous atoms you must break all of the bonds in 1 mole of gaseous SiH4 molecules. Calculate for that.
    Offline

    17
    ReputationRep:
    Can there not be enthalpies of atomisation for elements (1 mol of atoms) AND for compounds (1 mol of compound)?
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: January 21, 2015
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.