Types of Enthalpy...and what on earth they mean!

[redfox]

Ok so I'm having to pick up chemistry after 7 years of having nothing to do with it. I've searched around for tutorials on the different types and how they work, but I'm stuck with a couple of (simple) questions.

I need to write a balanced equation for:

 

Bromine gas to monatomic Bromine. I think this is:

Br2 -->2Br. I've been told it's enthalpy of hydration...but I'm not sure why that is!

 

Ok, second question is balancing Sodium gas to a sodium (I) cation.

What does the (I) mean? Just Na+? Is sodium not Na2+? Obviously I'm missing something here...also I need to state the type of enthalpy.

 

The last question is balancing monatomic bromine to a bromide anion and what kind of enthalpy is it.

 

 

Answers to any of these will be helpful, but perhaps some sort of explanation of what the different types of enthalpy are or links to a good tutorial site would be great!

Ta

[insane_alien]

I've been told it's enthalpy of hydration...but I'm not sure why that is!

 

I've always known that to be the enthalpy of atomisation.

 

Na+ is Na(I) since Na only has one valence electron any compunds it makes will involve Na(I). Enthalpy of ionisation IIRC.

 

Br -> Br- is enthalpy of affinity ... i think.

[hybrid04]

To be honest i never remember any of those names. All you really need to remember is its natural state is zero. So like O2 is zero (enthalpy of formation) if you go anywhere else it takes some amount of energy. The different "types" are really just some name to describe how you are changing the element/compound.

So to go from O2->2O takes some energy to bring it out of its natural state.

[redfox]

Ah, thankyou very much. Did come in handy!