1. The formula for ammonium cyanate is NH4(NCO), which is also written as [NH4+][NCO-]. The molecular formula of ammonium cyanate is CH4N2O Whereas the formula of urea is NH2CONH2 and molecular formula of ammonia is also CH4N2O.
In both the case molecular formula is actually same i.e. CH4N2O but structure is quite different.