The molar conductivities of KCl, NaCl and `KNO_(3)` are 152,128 and `111" S cm"^(2) mol^(-1)` respectively. What is the molar conductivity of `NaNO_(3)` ?

Options

A. 101 S `cm^(2)mol^(-1)`
B. 87 S `cm^(2)mol^(-1)`
C. `-101`S `cm^(2)mol^(-1)`
D. `-391`S `cm^(2)mol^(-1)`

Answer

B

Explanation

`wedge_(K^(+))^(@)+wedge_(Cl^(-))^(@)=152S" "cm^(2)mol^(-1)`
`wedge_(Na^(+))^(@)+wedge_(Cl^(-))=128S" "cm^(2)mol^(-1)`
`wedge_(K^(+))^(@)+wedge_(NO_(3)^(-))^(@)=111S" "cm^(2)mol^(-1)`
Now, `wedge_(NaNO_(3))=wedge_(NaCl)+wedge_(KNO_(3))-wedge_(KCl)`
`wedge_(NaNO_(3))=87S" "cm^(2)mol^(-1)`.