Ncert-class 11-chemistry – unit 7- Redox Reactions Welcome to your Ncert-class 11-chemistry - unit 7- Redox Reactions 1. The oxidation state of phosphorus is maximum in_________. $$phosphorus acid(𝐻_{3}PO_{3})$$ $$metaphosphoric acid (𝐻PO_{3})$$ $$phospine (𝑃𝐻_{3})$$ $$ diphosphine (P_{2}H_{4})$$ None 2. Which of the following statements is wrong? Oxidation number of oxygen is + 2 in oxygen difluoride Oxidation number of oxygen is − 2 in most of its compounds Oxidation number of oxygen is +1 in peroxides Oxidation number of oxygen is − 1 / 2 super oxides None 3. Oxidation state of nitrogen is not an integer in: $$hydroxyl amine (NH_{2}OH)$$ $$hydrazoic acid (N_{3}H)$$ $$ ammonia(NH_{3})$$ $$hydrazine (N_{2}H_{4})$$ None 4. What will be the reduction potential for the following half-cell reaction at 298K?(Given \([Ag^{+}])\=0.1M and E°cell =+0.80V) −0.741V −0.80V 0.741V 0.80V None 5. The oxidation state of A,B and C in compaund are -2, +5, and -2, respectively. the compound is ? $$A_2(BC)_{5}$$ $$A_2(BC)_{3}$$ $$A_3(BC)_{2}$$ None 6. Write balanced equations for the half reactions and calculate the reduction potentials at 25ºC for the following half cells : $$Cl^{-}(1.2M)|Cl_{2}(g,3.6atm)|PtE^{\cdot} =1.36V$$ 1.342V 1.372V 1.363V 1.358V None 7. The oxidation number of all the elements in the given compound is: Ethane \((C_{2}H_{6}))\ 3,0 3,-1 +3,+1 4,+1 None 8. The oxidation state of the metal atom is zero in: ferrous sulphate iron carbonyl ferric sulphate rust None 9. What is the oxidation number of 𝑀𝑛 in$$KMnO_{4}, K_{2}MnO_{4}, MnSO_{4}, MnO, Mn_{3}O_{4}$$ respectively +7,+6,+2,+3,+8/3 None of these +4,+6,+2,+4,+8/3 + 7 , + 6 , + 2 , + 4 , + 8/3 None 10. When a piece of sodium metal is dropped in water, hydrogen gas evolved because: water loses electrons and is oxidised to hydrogen water is oxidised and acts as a reducing agent sodium loses electrons and is oxidised while water in reduced sodium is reduced and acts as an oxidising agent None 11. In the conversion of $$Br_{2} to BrO_{3}^{-}$$ , the oxidation state of Br changes from: +1 to +5 0 to +5 0 to -3 +2 to +5 None 12. Find the oxidation number of elements in each case :S in Na_{2}S_{2}O_{3},S_{4}, S_{8}, Na_{2}S_{2}O_{7} None +1,0,0,+4 +1,0,+1,+6 +2,0,0,+6 None 13. Oxidation number of Cr is +5 in : $$K_{3}CrO_{8}$$ $$K_{2}CrO_{4}$$ $$[Cr(NH_{3})_{5}(H_{2}O)]Cl_{3}$$ $$(NH_{3})_{3}CrO_{4}$$ None 14. The oxidation number of oxygen in$$KO_{3},Na_{2}O_{2}$$ is 0,1 3,2 -0.33,-1 1,0 None 15. Two half-cells have potentials −0.44 and 0.799 volt respectively. These two are coupled to make a galvanic cell. Which of the following will be true? Electrode of half-cell potential − 0.44 𝑉 will act as cathode Electrode of half-cell potential − 0.44 𝑉 will act as a positive terminal Electrode of half-cell potential 0.799 𝑉 will act as anode Electrode of half-cell potential − 0.44 𝑉 will act as anode None 16. Alizarin belongs to the class of Mordant dye Vat dyes Reactive dye Basic dye None 17. Which of the following is a redox reaction? In atmosphere , formation of 𝑂3 from 𝑂2 by lightening Reaction of \(H_{2}SO_{4})\ with NaOH Evaporation of 𝐻 2 𝑂 Formation of oxides of nitrogen from nitrogen and oxygen by lightening. None 18. Oxidation number of Cl in 𝐾𝐶𝑙𝑂3 +1 -1 -5 +5 None 19. Which of the following species has an atom with +6 oxidation state? $$CrO_{2}Cl_{2}$$ $$NiF_{6}^{2-}$$ $$MnO_{4}^{-} $$ $$Cr(CN)_{6}^{3-}$$ None 20. In acid medium, the standard reduction potential of 𝑁𝑂converted to 𝑁2𝑂 is 1.59 𝑉. Its standard potential in alkaline medium would be: 0.062V 0.764V -1.59V -0.764V None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
