Lecture 31 11072008 - Announcements Hf:enthalpy...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Announcements
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Standard Heats of Formation Standard Heats of Formation ( H ° f ):  enthalpy  change for the formation of 1 mole of substance in  its standard state from its constituent elements in  their standard states. The standard heat of formation for any element in  its standard state is defined as being  ZERO . H ° f     =  0  for an element in its standard state Reference point from which all enthalpy changes are  measured
Background image of page 2
Standard Heats of Formation
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Standard Heats of Formation Calculating  H ° for a reaction: H ° reaction  =  H ° (Products) –  H ° (Reactants) For a balanced equation, each heat of formation  must be multiplied by the stoichiometric coefficient. a A +  b B         c C +  d D H ° = [ c H ° f    (C) +  d H ° f    (D)] – [ a H ° f    (A) +  b H ° f   
Background image of page 4
Standard Heats of Formation
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Example Calculate  H ° (in kilojoules) for the reaction of  ammonia with O 2  to yield nitric oxide (NO) and  H 2 O( g ), a step in the Ostwald process for the  commercial production of nitric acid. 4NH
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/29/2010 for the course CHM 2045 taught by Professor Brant during the Fall '08 term at University of South Florida.

Page1 / 24

Lecture 31 11072008 - Announcements Hf:enthalpy...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online