Acid-base titration & analytical chemistry

A 0.213-g sample of uranyl(VI)nitrate, UO2(NO3)2, is dissolved in 20.0 mL of 1.0 M H2SO4 and shaken with Zn. The zinc reduces the uranyl ion, UO2 (with a charge of 2+), to a uranium ion, Un+ (where n+ is the charge of the uranium ion). To determine the value of n, this solution is titrated with KMnO4. Permanganate is reduced to Mn2+ and Un+ is oxidized back to UO2(with a charge of 2+).
In the titration, 12.47 mL of 0.0173 M KMnO4 was required to reach the equivalence point. Use this information to determine the charge on the ion Un+.