[AqueleBurro]

Hey guys, this is my first post here. If anyone can help me, I had an experiment some time ago where I had to find out what the sample was through the observation of its reactions with some other compounds. The observations were:
- The sample is a strong alkali.
- When the sample was mixed with a solution of CuSO4, it reacted forming a blue precipitate.
- When the resulting sample was mixed with a concentrated solution of ammonia, it turned dark blue.
My guess is that the sample is NaOH and that the reactions were:
2NaOH + CuSO4 = Cu(OH)2 + Na2SO4
Cu(OH)2 + Na2SO4 + 4NH3 = [Cu(NH3)4(H2O)]SO4 + Na2O
Is this correct? I am almost sure that the sample is indeed NaOH, but I am not sure about the equations... Please, lemme know what you guys think and sorry for any grammar mistakes :s

[Borek]

First equation is OK, second - not so. You don't need the Na₂SO₄ on the left, it was just a spectator. Then, you put Na₂O on the products side - would it survive in water?

[AWK]

You run the reaction in an aqueous solution.
The complex is well soluble in water, so it's better to write ionic reactions. To be precise - the complex ion in water contains two coordinated water molecules and only one water molecule in solid-state.