Predict \Delta H for NaOH(s) to NaOH(g) using Hess' Law

[ghostanime2001]

NaOH(s) --> NaOH(g)

\Delta H^{\circ}_{diss} (O-O) = 251 kJ
\Delta H^{\circ}_{diss} (O-H) = 465 kJ
\Delta H^{\circ}_{diss} (H-H) = 435 kJ
\Delta H^{\circ}_{diss} (Na-O) = 255 kJ

\Delta H_{sol} = -46 KJ for NaOH_{(s)}

NaOH_{(s)} \rightarrow Na^{+}_{(aq)} + OH^{-}_{(aq)} \cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\Delta H = -46 KJ

\Delta H^{\circ}_{f} = -427 KJ for NaOH_{(s)}

Na_{(s)} + \frac{1}{2}O_{2(g)} + \frac{1}{2}H_{2(g)} \rightarrow NaOH_{(s)} \cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\Delta H = -427 KJ

I forgot one part:
Na_{(s)} \rightarrow Na_{(g)} \cdot\cdot\cdot\cdot\cdot \Delta H = 109 kJ

Predict \Delta H for NaOH_{(s)} \rightarrow NaOH_{(g)}


Because I am trying to find the enthalpy of one reaction, and i have other 'known' enthalpy reactions does this problem automatically turn into a Hess' Law type problem ? or is this still a bond energy/enthalpy reaction or just bond energy type problem ? Also i do not have a NaOH_{(g)} in any of my reaction so how can i go about computing the targeted enthalpy ?

 

[ghostanime2001]

So does anyone know how to tackle this problem ?

 

[ghostanime2001]

Okay here is what i tried doing, I know there might be something wrong and such but please please please i beg you indicate my mistake this is my last question regarding Reaction heats. Next up Equilibrium lol ... anyways.. *ahem*...

Na_{(s)} \rightarrow Na_{(g)} \cdot\cdot\cdot\cdot\cdot \Delta H=109 KJ
This means:

Na_{(g)} + \frac{1}{2}O_{2(g)} + \frac{1}{2}H_{2(g)} \rightarrow NaOH_{(s)} \cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot \Delta H^{\circ}_{f} = -268 KJ

My question regarding the above question is when i convert Na(s)-->Na(g) does my product NaOH(s) become ---> NaOH(g) so that my target equation ends up NaOH(g) as a product ? or does it still remain a solid and my calculation or method is wrong and should be discarded because a better method is out there... so please help. I did another part it seems to make sense to change NaOH(s) ---> NaOH(g) because I am using the heat of dissociation and do those values mean to dissociate a given compound to its gaseous atoms or what ??. I know that those values are the same for any compound so does that also mean its the same values for the same compound but in a different state like with NaOH(s) and NaOH(g) ?

I converted NaOH(s) into NaOH(g) to show my method but still i need a better explanation so i can understand and not just from theorizing "making things happen" which i don't like to do :( I also know this is sublimation lol that's my last point. I got -268 KJ for the second equation because I am using bond energies or is this still not the correct method ? please help me.

NaOH_{(s)} \rightarrow Na_{(s)} + \frac{1}{2}O_{2(g)} + \frac{1}{2}H_{2(g)} \Delta H = 427 KJ
Na_{(g)} + \frac{1}{2}O_{2(g)} + \frac{1}{2}H_{2(g)} \rightarrow NaOH_{(g)} \Delta H = -268 KJ
==========================================
NaOH_{(s)} \rightarrow NaOH_{(g)} \Delta H = 159 KJ

You can do the cancellation yourself: Na, O2, and H2 get cancelled. This answer is correct on the back of my paper but can anyone suggest a better method ? of if this is somewhat the correct method then can anyone please clean up my explanation to make things clear ? Thanks a bunch. Now i go sleep ... ZZZzz

 

[ghostanime2001]

CAN somebody help me with this ?

 

[ghostanime2001]

Helooooooooooooooooooooooo ? Is there anyone in this forum ?