The limiting molar conductivities `^^ ^(@)` for NaCl , KBr , and KCl are 126 , 152 and 150 `S cm^(2) mol^(-1)` respectively. The `^^ ^(@)` for NaBr_________.

Options

A. `128 S cm^(2) mol^(-1)`
B. `302 S cm^(2) mol^(-1)`
C. `278 S cm^(2) mol^(-1)`
D. `176 S cm^(2) mol^(-1)`

Answer

A

Explanation

`^^""_(Nacl)^(@)=lambda_(Na)^(@)+lambda_(Cl)^(@)=126" "...(1)`
`^^""_(KBr)^(@)=lambda_(K^(+))^(@)+lambda_(Br^(-))^(@)=152" "...(2)`
`^^""_(KCl)^(@)=lambda_(K^(+))^(@)+lambda_(Cl^(-))^(@)=150" "...(3)`
`^^""_(NaBr)^(@)=lambda_(Na)^(@)+lambda_(Br^(-))^(@)`
`^^""_(NaBr)^(@)=126+152-150=128`