According to the balanced equation below, how many moles of #ClO^-2 (aq)# are needed to react completely with 20. mL of 0.20 M #KMnO_4# solution?
#2H_2O(l) + 4MnO_4(aq) + 3ClO_2^(-)(aq) -> 4MnO_2(s) + 3ClO_4^(-)(aq) + 4OH^(-)(aq)#
Given the equation, we need 3/4 equiv of chlorite anion,
What would you observe in this reaction? What was the macroscopic colour change?