Question

The pair(s) of reagents that yield paramagnetic species is/are
A. Na and excess of `NH_(3)`
B. `K` and excess of `O_(2)`
C. Cu and dilute `HNO_(3)`
D. `O_(2)` and 2-ethylanthraquinol

Answer 1

Correct Answer - A::B::C
`Na + underset("(excess)") ((x + y) ) NH_(3) to [Na(NH_(3))]^(+) + e^(-) (NH_(3))_(y)` Solvated or ammoniated electron which is paramagnetic .
(b) `K + underset("(excess)")(O_(2)) to underset("(paramagnetic)")(KO_(2) ("potassium superoxide"))`
(c) ` 3 Cu + 8 HNO_(3) ("dil.") to 3 Cu(NO_(3))_(2) + 4 H_(2)O + underset("(paramagnetic)")(2 NO)`
(d) ` O_(2)` and 2-ethylanthraquinol react to produce `H_(2)O_(2)` which is not paramagnetic but is diamagnetic .