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Chromium metal is electroplated using an...

Chromium metal is electroplated using an acidic solution containing `CrO_3` according to the following equation:
`CrO_3(aq)+6H^+6e^(-)rarr Cr(s)+3H_2O`
Calculate how many grams of chromium using 12.5 A current ? [Atomic mass of `Cr= 52 g mol^(-1),1F=96000 C mol ^(-1)]`

Text Solution

Verified by Experts

(i) Eq. wt. of Cr `=("Atomic weight")/("Change of oxidation number per mole")=(52)/(6)`
96500 coulomb deposit `=(52)/(6)` gm (Cr)
24000 coulomb will deposite `=(52)/(6) xx (2400)/(96500)gm =2.1554` gm of Cr
`W_(Cr)=1.5gm i=12.5"ampere"`
`E_(Cr)=(52)/(6), t=?`
`W=("Eit")/(96500) rArr 1.5 =(52 xx 12.5 xx t)/(6 xx 96500)`
t=1336.15 second
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