The 14 Bottle Problem - Zn(NO3)2 vs. Al(NO3)3?

i just started the same exact ignment and those 2 will definetly be a problem in the future. maybe if you boil the samples,u can look at just the salt? other than that im not sure. actually i just found a website that says zinc nitrate will form a precipitate with ammonia, or your NH4OH solution. try that. boiling point should be greater for the aluminum solution i think also.(more ions)