Precipitate predictions?

Question

Using this question as an example: Copper(II) sulphate is added to sodium hydroxide, write a balanced equation, if no reaction, write "no reaction" ... i know how to answer the question, but have forgotten how to do that table to predict the products of those two reactants

The table goes like:
........XX XX
XX
XX
with the four gaps being the potential products ... can anyone remind me how to do this? Sorry if thats confusing, I'm not sure how to explain it better :S I appreciate the help though.

Answer 1

Which sylllabus ????????? Better refer your textbook.

Answer 2

perform the reaction - write the products. This is a double replacement reaction so switch partners.

Cu+2 SO4-2 make up CuSO4

Na+1 OH-1 make up NaOH

So switch species around remembering that +/+ and -/- never ever go together

CuSO4 + NaOH ----> Na2SO4 + Cu(OH)2

Then balance

CuSO4 + 2NaOH ----> Na2SO4 + Cu(OH)2

I don't know WHAT x's you are talking about - I have never ever heard of x's. If you want to know if a ppt forms, use your solubility rules.

Rule 1 (in most texts anyway) states that all group 1 cations are soluble species, meaning they will not form a ppt in a reaction

a later rule states that almost all hydroxides are insoluble (except, Ba(OH)2, Ca(OH)2, Sr(OH)2 (your strong bases) and hydroxides with group 1 cations) this means that copper (II) hydroxide will form a solid so this is a reaction and your ppt is Ca(OH)2