MCQs on Oxidation Number and Oxidation State
1. Number of moles of K2Cr2O7 reduced by 1 mole of Sn2+ is
(a)1/6
(b)1/3
(c)2/3
(d)1
Answer:::: (b)
2. The oxidation number of carbon in CH2Cl2 is
(a)0
(b)2
(c)3
(d)5
Answer:::: (a)
3. Which of the following will not be oxidised by O3?
(a)KI
(b)FeSO4
(c)KMnO4
(d)K2MnO4
Answer:::: (c)
4. The oxidation state of chromium in the final product formed by the reaction between KI and acidified potassium dichromate solution is
(a)+4
(b)+6
(c)+2
(d)+3
Answer:::: (d)
5. What products are expected from the disproportionation reaction of hypochlorous acid?
(a)HCl and Cl2O
(b)HCl and HClO3
(c)HClO3 and Cl2O
(d)HClO2 and HClO4
Answer:::: (b)
6. Which of the following elements does not show disproportionation tendency?
(a)Cl
(b)Br
(c)F
(d)I
Answer:::: (c)
7. What is the oxidation number of chlorine in HClO4?
(a)+3
(b)+5
(c)+7
(d)+8
Answer:::: (c)
8. The oxidation state of each Cl in CaOCl2 is
(a)0
(b)+1
(c)-1
(d)+1, -1
Answer:::: (d)
9. The products formed when an aqueous solution of NaBr is electrolysed in a cell having inert electrodes are
(a)Na and Br2
(b)Na and O2
(c)H2, Br2, NaOH
(d)H2 and O2
Answer:::: (c)
10. Number of moles of MnO4– required to oxidise one mole of ferrous oxalate completely in the acidic medium will be
(a)7.5 moles
(b)0.2 moles
(c)0.6 moles
(d)0.4 moles
Answer:::: (c)
