d and f BLOCK ELEMENTS

What is the oxidation state of sulfur in the sulphate ion (SO4^2-)?

• +4
• +6
• +2
• +8

What is the oxidation state of sulfur in the thiosulphate ion (S2O3^2-)?

• +6
• +4
• +2
• 0

What is the oxidation state of manganese in the permanganate ion (MnO4^-)?

• +6
• +7
• +8
• +5

What color change is typically observed at the endpoint of a permanganate titration?

• From blue to red
• From yellow to orange
• From colorless/pale pink to intense purple
• From green to brown

In the reaction 2MnO4^- + 3Mn^2+ + 2H2O → 5MnO2 + 4H+, what is the stoichiometric coefficient of MnO2 in the products?

• 1
• 2
• 3
• 5