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महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

Calculate Ecell∘ of the following galvanic cell: Mg(s) / Mg2+(1 M) // Ag+ (1 M) / Ag(s) if EMg∘ = – 2.37 V and EAg∘ = 0.8 V.

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प्रश्न

Calculate `"E"_"cell"^circ` of the following galvanic cell:

Mg(s) / Mg2+(1 M) // Ag+ (1 M) / Ag(s) if `"E"_"Mg"^circ` = – 2.37 V and `"E"_"Ag"^circ` = 0.8 V. Write cell reactions involved in the above cell. Also mention if cell reaction is spontaneous or not.

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उत्तर

Given: `"E"_"Mg"^circ` = – 2.37 V and `"E"_"Ag"^circ` = 0.8 V

To find: Standard cell potential

Formula: `"E"_"cell"^circ = "E"_"cathode"^circ - "E"_"anode"^circ`

Calculation: `"E"_"cell"^circ = "E"_"cathode"^circ - "E"_"anode"^circ`

`"E"_"cell"^circ = "E"_"Ag"^circ - "E"_"Mg"^circ`

= (0.8 V) - (- 2.37 V) = 3.17 V

The standard cell potential for the reaction is 3.17 V.

Cell reactions:

Electrode reactions are

At anode: \[\ce{Mg_{(s)} -> Mg^{2+}_{ (aq)} + 2e-}\]
At cathode: \[\ce{Ag^+_{ (aq)} + e^- -> Ag_{(s)}}\]
Overall cell reaction- \[\ce{Mg_{(s)} + 2Ag^+_{ (aq)} -> Mg^{2+}_{ (aq)} + 2Ag_{(s)}}\]

Since the standard cell potential is positive, the cell reaction is spontaneous.

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पाठ 5: Electrochemistry - Long answer questions

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