108 g of silver (molar mass 108 g mol–1) is deposited at cathode from AgNO3(aq) solution by a certain quantity of electricity. The volume (in L) of oxygen gas produced at 273 K and 1 bar pressure from water by the same quantity of electricity is _______.
Answer (integer)
5
Solution
Cathode : Ag<sup>+</sup>(aq) + e<sup>-</sup> $\to$ Ag(s)
<br><br>Moles of Ag deposited = ${{108} \over {108}}$ = 1 mole
<br><br>Anode : 2H<sub>2</sub>O $\to$ O<sub>2</sub> + 4H<sup>+</sup> + 4e<sup>-</sup>
<br><br>Here we have to find volume of O<sub>2</sub> evolved.
<br><br>Equivalance of Ag = Equivalance of O<sub>2</sub>
<br><br>$\Rightarrow$ 1 $\times$ 1 = n<sub>O<sub>2</sub></sub> $\times$ 4
<br><br>$\Rightarrow$ n<sub>O<sub>2</sub></sub> = ${1 \over 4}$ mol
<br><br>$\therefore$ Volume of O<sub>2</sub> evolved
<br><br>= ${1 \over 4}$ $\times$ 22.4
<br><br>= 5.6 lit
About this question
Subject: Chemistry · Chapter: Electrochemistry · Topic: Electrochemical Cells
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