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The negative Zn pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by 0.13 g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is

  • Option 1)

    0.180 g

  • Option 2)

    0.141 g

  • Option 3)

    0.126 g

  • Option 4)

    0.242 g.

 

Answers (2)

best_answer

As we discussed in

Faraday sec law of electrolysis -

m= zq

\frac{m_{1}}{m_{2}}= \frac{z_{1}}{z_{2}}

- wherein

Electrochemical equivalent is mass of ions deposited or liberated during electrolysis.

 

 

 

 According to Faraday's law of electrolysis

\frac{m_{zn}}{m_{cu}} = \frac{Z_{zn}}{Z_{cu}}

when i and t are same

\therefore \frac{0.13}{m_{cu}}=\frac{32.5}{31.5}

= m_{cu} = \frac{0.13\times 31.5}{32.5}

= 0.126 g


Option 1)

0.180 g

This option is incorrect.

Option 2)

0.141 g

This option is incorrect.

Option 3)

0.126 g

This option is correct.

Option 4)

0.242 g.

This option is incorrect.

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