What will be the molar conductivity of Al 3+ ions at infinite dilution if molar conductivity of `Al^(2) (SO_(4))_(3)` is 858 S `cm^(2)` `"mol" ^(-1)` and ionic conductance of `SO_(4)^(2-)` is 160 S `cm^(2) "mol" ^(-1)` at infinite dilution ?

Options

A. 189 S `"cm"^2 "mol"^(-1)`
B. 698 S `"cm"^2 "mol"^(-1)`
C. 1018 S `"cm"^2 "mol"^(-1)`
D. 429 S `"cm"^2 "mol"^(-1)`

Answer

A

Explanation

`Lambda_(Al_2(SO_4)_3)^@=2Lambda_(Al^(3+))^@+3Lambda_(SO_4^(2-))^@`
`Lambda_(Al^(3+))^@=(Lambda_(Al_2(SO_4)_3)^@-3Lambda_(SO_4^(2-))^@)/2`
`=(858-(3xx160))/2=189 S cm^2 mol^(-1)`