Arrange the following in the order of their decreasing electrode potentials:Mg, K, Ba,Ca

Options

A. K, Ca, Ba, Mg
B. Ba, Ca, K, Mg
C. Ca, Mg, K, Ba
D. Mg, Ca, Ba, K

Answer

D

Explanation

(d) Order of decreasing electrode potentials of Mg, K, Ba and Ca is `Mg gt Ca gt Ba gt K`
It can be explained by their standard reduction or potentials.
`E_(k^(+)|K)^(circ) = -2.925 V, E_(Ba^(2+)|Ba) = -2.90 V`
`E_(Ca^(2+)|Ca)^(circ) = -2.37 V, `
Highly negative value of `E_(red)^(circ)` shows the least value of electrode potential.