Question

Question #a1a20

Answer 1

`8"hr""12min"`

Explanation:

`Zn^(2+)+2erarrZn`

1 mole of `Zn` requires 2 moles of electrons to be discharged.

The amount of charge carried by 1 mole of electrons can be found by multiplying the electronic charge by the Avogadro Constant.

This is termed the Faraday Constant `F`.

`F=9.648xx10^(4)"C/mol"`

1 mole `Zn` requires 2 Faradays of charge to be discharged so:

`65.4g"rarr2F`

`:.0.5"g"rarr(2)/(65.4)xx0.5""F`

`0.5"g"rarr0.0153F`

The amount of charge in Coulombs this amounts to is given by:

`Q=0.0153xx9.648xx10^4"C"`

`=1475.2"C"`

If a current of 1 amp flows for 1 second then 1 Coulomb of charge is passed.

So:

`I=Q/t`

`:.t=Q/I`

`t=1475.2/0.05`

`t=29504.6s`

`t=29504.6/60=491.7"min"`

`t=491.7/60=8.2"hr"`

`t=8"hr"""12"min"`