48) What will be the oxidation state of copper in YBa₂Cu₃O₇, if oxidation state of Y is +3?

49) How many moles of nitrogen are produced by the oxidation of one mole of hydrazine by 2⁄3 mol bromate ion?

50) How many moles of K₂Cr₂O₇ are reduced by 1 mole of formic acid?

51) One mole KMnO₄ oxidises how many moles of ferrous oxalate?

52) How many mL of 0.1M oxalic acid solution is required to reduce 0.01 mol KMnO₄ to MnO₂?