Writing dissociation equations when substance is dissolved in water

[littlelacy]

So I have to write a bunch of dissociation equations when certain substances are dissolved in water.
Ex] HF_(g)
But I have no clue what to do. Help

[ChemHelper]

Okay, first you want to know your rules of solubility to know whether or not something is soluble in water or not. Then, once you know it is soluble you need to identify what makes up the compound of interest.

For example, let's look at sodium chloride (NaCl). We know that it is made up of one Na atom and one chlorine atom so when it dissociates it will become a sodium ion (Na⁺) and a chloride ion (Cl^-).

It will also help you to know the common ions. You can find a list of these in most chem books or online. If you go to google and search common ions it will give you a list of them, both monoatomic and polyatomic ions and their charges as well.

With this information, can you tell us now what you think will happen to HF in water? Let us know what you think and we can go from there.

Good luck!!!

[ChemHelper]

Sorry, I forgot to show you how to write the equation from my example.

NaCl + H₂O ----> Na⁺_(aq) + Cl^-_(aq)

[littlelacy]

would it be:
HF + H₂O ----> H⁺ + F^-

[ChemHelper]

That looks good to me. Nice work.   

[littlelacy]

Thanks, so for like a problem with like more subscripts and stuff such as
Al₂(SO₄)₃(s)
would be like:
Al₂(SO₄)₃(s) + H₂O ---> Al²⁺ + SO₄^3-
??

[ChemHelper]

You're welcome. 

This one looks good to me as well but don't forget to put the coefficients in front of the products. Also, it's just a minor mistake but you have your charges mixed up in the product side of this example. So in this case, you need to have a 2 in front of the Al⁺³ and a 3 in front of the SO₄^-2

Good luck and keep up the hard work!