A student made the following observations in the laboratory, i) Clean copper metal did not react with 1 molar ${\rm{Pb}}{\left( {{\rm{N}}{{\rm{O}}_3}} \right)_2}$ solution. ii) Clean lead metal dissolved in a 1 molar ${\rm{AgN}}{{\rm{O}}_3}$ solution and crystals of ${\rm{Ag}}$ metal appeared. iii) Clean silver metal did not react with 1 molar ${\rm{Cu}}{\left( {{\rm{N}}{{\rm{O}}_3}} \right)_2}$ solution. The order of decreasing reducing character of the three metals is :

${\rm{Pb}},{\rm{Cu}},{\rm{Ag}}$

${\rm{Cu}},{\rm{Pb}},{\rm{Ag}}$

${\rm{Cu}},{\rm{Ag}},{\rm{Pb}}$

${\rm{Pb}},{\rm{Ag}},{\rm{Cu}}$

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JEE CHEMISTRY MCQ: ELECTRO CHEMISTRY

1 Hard

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Analyzing +4 | -1

A student made the following observations in the laboratory,
i) Clean copper metal did not react with 1 molar

\mathrm{Pb}{\left( {\mathrm{N}{\mathrm{O}_3}} \right)_2}

solution.
ii) Clean lead metal dissolved in a 1 molar

\mathrm{AgN}{\mathrm{O}_3}

solution and crystals of

\mathrm{Ag}

metal appeared.
iii) Clean silver metal did not react with 1 molar

\mathrm{Cu}{\left( {\mathrm{N}{\mathrm{O}_3}} \right)_2}

solution.
The order of decreasing reducing character of the three metals is :

View answer and explanation

Correct option: C

\mathrm{Pb},\mathrm{Cu},\mathrm{Ag}

Option C (Pb, Cu, Ag) is correct because lead dissolved in silver nitrate, copper did not react with lead nitrate, and silver did not react with copper nitrate, indicating the decreasing order of reducing power.

More Questions from ELECTRO CHEMISTRY

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25^{\circ} \mathrm{C}

, the standard emf of cell having reactions involving two electron change is found to be

0.295 \mathrm{~V}

. The equilibrium constant of the reaction is Which are used as secondary reference electrodes? For the following cell with hydrogen electrodes at two different pressures

{p_1}{\kern 1pt} {\kern 1pt} \mathrm{and}{\kern 1pt} {\kern 1pt} {p_2}

\mathop {\mathrm{Pt}\left( {{\mathrm{H}_2}} \right)}\limits_{{p_1}} \left| {\mathop {{\mathrm{H}^ + }\left( {aq} \right)}\limits_{1\mathrm{ }M} } \right|\mathop {Pt\left( {{\mathrm{H}_2}} \right)}\limits_{{p_2}}

emf is given by A current of strength 2.5 A was passed through

\mathrm{CuS}{\mathrm{O}_4}

solution for 6 min 26 s. The amount of copper deposited is (At. Wt. of Cu = 63.5, 1F = 96500 C) A current strength of 9.65 amperes is passed through excess fused

{AlCl}_3

for 5 hours. How many litres of chlorine will be liberated at

STP

({F}=96500 {C})

The electrode potential (in millivolts) of

2 \mathrm{Ag}(\mathrm{s})+\mathrm{S}^{2-}(\mathrm{aq}) \rightarrow \mathrm{Ag}_2 \mathrm{S}(\mathrm{s})+2 \mathrm{e}^{-}

in a solution buffered at

\mathrm{pH}=3

and which is also saturated with

0.1 \mathrm{~M}-\mathrm{H}_2 \mathrm{S},

is (Given: for

\mathrm{H}_2 \mathrm{S}, K_{\mathrm{a}_1}=10^{-8} ; K_{\mathrm{a}_2}=10^{-13}, K_{\mathrm{sp}}

\mathrm{Ag}_2 \mathrm{S}=4 \times 10^{-48},

E^{\circ}_{{\mathrm{Ag} | \mathrm{Ag}}^{+}}=0.80 \mathrm{~V},

\log 2=0.3,

2.303 R T / F=0.06

)