jee adv old papers

Question

The pair(s) of reagents that yield paramagnetic species is/are

Answer 1

The correct options are a,b,c

• Dilute solution of Na in liquid ammonia is paramagnetic due to ammoniated e⁻¹s

Na^⊕ + (x+y)NH₃ →Na⁺(NH₃)x + e.(NH₃)y

K + O₂(excess) → KO₂ Paramagnetic

• \(O_{-2}\) is paramagnetic due to unpaired electron in antibonding orbital

3Cu + 8HNO₃(diluted) → 3Cu(NO₃)₂ + 2NO + 4H₂O

• NO is paramagnetic due to unpaired electrons on ''N''.

where ''H₂O₂'' is diamagnetic.