[antimech]

I've been doing a couple of lab experiments on Grignard principals, but I have trouble understanding each step.

For example, I added aqueous ammoniumchloride and ice to hydrolyze the mixture of acetone and isopropylbromide. Is this called protonation, if the ammonium gives up a hydrogen atom as the bond to its compound breaks?
What would then happen if ammoniumchloride was to be replaced by concentrated sulphuric acid? Would I not get alcohol as the product? Why or why not?

I can't understand this based on what my textbook says... 

[AWK]

Alcohols react with concentrated H2SO4

[antimech]

But the aqueous ammoniumchloride solution is used to make the alcohol?? If I did not use the ammoniumchloride to hydrolyze the solution of acetone and isopropylbromide (before the alcohol is formed), and instead use the sulphuric acid - what would the result be? Would the sulphuric acid perhaps lead to dehydration - and not result in a R-OH product?

[AWK]

Isopropyl bromide after A Grignard reaction?
Always an excess of Mg is used.
Write down a reaction and look what can be hydrolysed.

Ammonium chloride gives pH about 4 (this pH is sufficient to decompose a Grignard product ROMgBr), but it also shows a salting effect.
Your resulting alcohol is a liquid (2,3-dimethylbutanol-2 - I do hope I guess your mysterious reaction) and is slightly soluble in water. Any salt diminishes this solubility.