PrepBharat

1. Chlorine cannot displace
a) Fluorine from NaF
b) Iodine from NaI
c) Bromine from NaBr
d) None of these

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2. Standard potentials (E°) for some half-reactions are given below :
(I) \[Sn ^{4+} +2e\rightarrow Sn ^{2+};E ^{\circ}= +0.15V\]
(II) \[2Hg ^{2+} +2e\rightarrow Hg_2^{2+};E ^{\circ}= 0.92 V .\]
(III) \[PbO_{2} +4H^{+}+2e\rightarrow Pb^{2+}+2H_{2}O;E ^{\circ}= +1.45V\]
based on the above, information which one of the following statements is correct?
a) \[Sn^{4+}\]  is a stronger oxidising agent than \[Pb^{4+}\]
b) \[Sn^{2+}\]  is a stronger reducing agent than \[Hg_{2}^{2+}\]
c) \[Pb^{2+}\]  is a stronger oxidising agent than \[Pb^{4+}\]
d) \[Pb^{2+}\]  is a stronger reducing agent than \[Sn^{2+}\]

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3. The oxidation potentails of A and B are +2.37 and +1.66 V respectively. In chemical reactions
a) A will be replaced by B
b) A will replace B
c) A will not replace B
d) A and B will not replace each other

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4. Electrode potential data are given below :
\[Fe^{+3}\left(aq\right)+e^{-}\rightarrow Fe^{+2}\left(aq\right);E° = +0.77 V\]
\[Al^{3+}\left(aq\right)+3e^{-}\rightarrow Al\left(s\right);E° = – 1.66 V\]
\[Br_{2}\left(aq\right)+2e^{-}\rightarrow 2Br^{-}\left(aq\right);E° = + 1.08V\]
Based on the data, the reducing power of \[Fe^{2+}\]  , Al and \[Br^{-}\] will increase in the order
a) \[Br^{-}< Fe^{2+} < Al\]
b) \[ Fe^{2+}< Al < Br^{-}\]
c) \[ Al < Br^{-}< Fe^{2+}\]
d) \[ Al< Fe^{2+}< Br^{-}\]

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5. Choose the correct statement from the following which is related to the electrochemical series
a) Electrochemical series is not the arrangement of metals and ions according to their reactivity
b) The metal ions at the top of the electrochemical series are highly electronegative
c) Strongly electropositive metals can displace weakly electropositive metals from their salt solution
d) All metals above hydrogen in the series do not displace hydrogen from dilute acids

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6. The standard reduction potentials of four elements are given below. Which of the following will be the most suitable reducing agent?
I = –3.04 V
II = – 1.90 V
III = 0 V
IV = 1.90 V
a) III
b) II
c) I
d) IV

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7. The standard reduction potentials at 298K for the following half reactions are given against each
\[Zn^{2+}\left(aq\right)+2e\rightleftharpoons Zn\left(s\right); –0.762 V\]
\[Cr^{3+}\left(aq\right)+3e\rightleftharpoons Cr\left(s\right); –0.740 V\]
\[2H^{+}\left(aq\right)+2e\rightleftharpoons H_{2}\left(g\right); 0.00 V\]
\[Fe^{3+}\left(aq\right)+e\rightleftharpoons Fe^{2+}\left(aq\right); 0.770 V\]
Which is the strongest reducing agent?
a) \[Zn\left(s\right)\]
b) \[Cs\left(s\right)\]
c) \[H_{2}\left(g\right)\]
d) \[Fe^{3+}\left(aq\right)\]

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8. Zn gives H₂ gas with \[H_{2}SO_{4}\]  and HCl but not with \[HNO_{3}\]  because
a) Zn acts as oxidizing when reacts with \[HNO_{3}\]
b) \[HNO_{3}\]  is weaker acid than \[H_{2}SO_{4}\]  and HCl
c) In electrochemical series Zn is above hydrogen
d) \[NO_3^-\] is reduced in preference to hydronium

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9. A smuggler could not carry gold by depositing iron on the gold surface since
a) gold is denser
b) iron rusts
c) gold has higher reduction potential than iron
d) gold has lower reduction potential than iron

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10. The metal that cannot displace hydrogen from dilute hydrochloric acid is
a) aluminium
b) Iron
c) copper
d) zinc

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