[raymas8]

will NH4Cl react with H2SO4 to form a product? HCl and ?

[mike]

more likely:

NH3 + H2SO4 -----> (NH₄)₂SO₄ or something similar.

Where did you get this reaction, usually acids react with bases..

[raymas8]

well im trying to figure out if a mixture with the two and maleic acid will produce fumaric acid. Im pretty sure that the H2so4 alone will isomerize maleic acid to fumaric acid but im not sure if the NH4Cl and sulfuric acid with react with eachother instead of with the the maleic acid.

[Dude]

Not recommended.

My concern would be if HCl would be generated by displacement of HCl with HS04-.  If the chorine in sodium chloride can be displaced to generate HCl, I would have to do a test to see if you generate HCl before adding NH4Cl (or not filtering it out, however it got there).  

The implication would then be if HCl can react with the double bond.

[HP]

I think this reaction will occur:
2NH4Cl + H2SO4conc = (NH4)2SO4 +  HClgas