Solid State Enthalpy
 |
 HONEYWELL CARRIER SOLID STATE ENTHALPY SENSOR HH57AC078A NEW IN BOX  US $15.00
|
 New Honeywell C7400A 1004 Solid State Enthalpy Sensor for Economizer US $14.95
|
How do I calculate the enthalpy change of this?
Calculate the entalphy change of the reaction
Na(s) + 1/2 Br2(g) ---> NaBr (s)
I'm given the following information
ΔH of atomisation (Na) = +107 kJ/mol
ΔH of atomisation (Br) = +97 kJ/mol
ΔH first ionisation energy (Na) = +496 kJ/mol
ΔH first electron affinity (Br) = -325kJ/mol
ΔH lattice energy (NaBr) = -742 kJ/mol
Should I use all the information given above? I'm pretty sure the lattice energy given is redundant since the equation stated the solid state of Na and not the gaseous state. Please help me! Thanks.
Yes, you should use all the information given above.
This is how to it ( no full answer, just a guidance )
-
1. Atomisation of Na
Na(s) + 1/2Br2(g) ==> Na(g) + 1/2Br2(g)
2. Ionisations of Na
Na(g) + 1/2Br2(g) ==> Na+(g) + 1/2Br2(g)
3. Atomisation of Br
Na+(g) +1/2Br2(g) ==> Na+(g) + Br(g)
4. Electron Affinities of Br
Na+(g) + Br(g) ==> Na+(g) + Br-(g)
5. Lattice Energy of NaBr
Na+(g) + Brˉ(g) ==> NaBr(s)
6. Formation of NaBr
Na(s) + 1/2 Br2(g) ---> NaBr (s)
You should notice that overall equation #6 is the same as going stepwise from #1 through to #5.
You have to draw Born Hyber Cycle .
Hess's Law and Reaction Enthalpy Change
You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
Comments are closed.