What is the Enthalpy Change for NaOH(s) to NaOH(g)?

[ghostanime2001]

Enthalpy of NaOH(s) --> NaOH(g)

Homework Statement

Given:
1. Na_{(s)} \rightarrow Na_{(g)} \Delta H = 109 kJ

2. \Delta H^{\circ}_{diss} = 251\:kJ\:for\:O_{2}

3. \Delta H^{\circ}_{diss} = 435\:kJ\:for\<img src="/styles/physicsforums/xenforo/smilies/arghh.png" class="smilie" loading="lazy" alt=":H" title="Gah! :H" data-shortname=":H" />_{2}

4. \Delta H^{\circ}_{diss} = 465\:kJ\:for\:O-H

5. \Delta H^{\circ}_{diss} = 255\:kJ\:for\:Na-O

6. \Delta H_{soln} = -46\:kJ\:for\:NaOH_{(s)}

7. \Delta H^{\circ}_{f} = -427\:kJ\:for\:NaOH_{(s)}

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

Homework Equations

see above

The Attempt at a Solution

I understand the standard states of all substances for #1-3 but I am unsure of #4,5,7. I don't understand what the standard states are for #4,5 (both reactants and products). I don't understand what the physical state of sodium is for #7 (is it solid or gas ?). Also how will the aqueous ions produced from dissociation of sodium hydroxide in #6 cancel out ? and how will covalent bonds of Na-O or O-H as reactants cancel out ?

Thanks! :)

 

[Borek]

You can assume bond dissociation enthalpy doesn't depend on the state. In #7 you start with elements in the standard state and end with NaOH in the standard state.

 

[ghostanime2001]

How will I cancel aqueous hydroxide ion or sodium cation ? So the standard state of elemental sodium in #7 is solid ? Also, after O--H bond or Na--O bond dissociates do the Na or O or H assume a gaseous state ?

 

[ghostanime2001]

Any new thoughts from my previous reply ?