`Na-` amalgam is prepared by electrolysis of `NaCl` solution using liquid `Hg` as cathode . How long should the current of `10 amp`. Is passed to produce `10% Na-Hg` on a cathode of `10gm Hg`. ( atomic mass of `Na=23)`.

Options

A. 7.77 min
B. 9.44 min
C. 5.24 min
D. 11.39 min

Answer

A

Explanation

90 gm Hg has 10 gm Na
`therefore10gmHg=(10)/(90)xx10=(10)/(9)gmNa`
`therefore` weight of Na`=(M)/(n)xx(ixxt)/(96500)`
`(10)/(9)=(23)/(1)xx(10xxt)/(9xx10xx23)` `[therforeNa^(+)+etoNa]`
`thereforet=(10xx96500)/(9xx10xx23)=7.77min`