Commercial brass, an alloy of Zn and Cu, reacts with hydrochloric acid as follows.

Zn(s) + 2 HCl(aq) --> ZnCl2(aq) + H2(g)

(Cu does not react with HCl.) When 0.5029 g of a certain brass alloy is reacted with excess HCl, 0.0901 g ZnCl2 is eventually isolated. and then i need the %Zn and %Cu

So i start by taking 0.0901g/136.2884g(1mol ZnCl2) = 0.00661098083182 mol, so 0.5029g is 0.00661098083182 mol of this Zn and Cu alloy, so the atomic weight of Zn is 65.382 so we take 0.00661098083182*65.382 = 0.43224g... so 0.43324/0.5029 gives me the percent of Zn to the total compound which is 86.15% and the % Cu would just be 100-86.15= 13.85 but apparently thats wrong.. can someone tell me where i went wrong?