Fill-in-the blank.  Make sure to include the plus and negati…

Fill-in-the blank.  Make sure to include the plus and negative signs.  Do not write spaces.  (Example: If the answer is positive four enter +4 not + 4).  The sulfur atom in the sulfite ion, SO32-, has an oxidation number of [1].  The oxidation number of the number of bromine in Br2 is [3]. The aluminum atom in aluminum hydride, AlH3, has an oxidation number of [2].

Chromium(VI)  is considered a hazardous, carcinogenic specie…

Chromium(VI)  is considered a hazardous, carcinogenic species, destruction of which may be accomplished by the process shown in the balanced equation below:             4 Zn (s) + K2Cr2O7 (aq) + 7 H2SO4 (aq) → 4 ZnSO4 (s) + 2 CrSO4 (s) + K2SO4 (aq) + 7 H2O (l) Which is the limiting reactant when 5.00 moles of Zn and 2.00 moles of  K2Cr2O7 react in excess H2SO4?