gate questions

Q. Second-order rate constant for the reaction between [Co(NH3)5X]n+ (n = 3 for X = NH3 and H2O; n = 2 for X = Cl–) and [Cr(H2O)6]2+ at room temperature varies with the X as (A) NH3 > H2O > Cl–                  (B) Cl– > H2O > NH3 (C) NH3 > Cl– > H2O                    (D) H2O > […]

Q. Generally, the coordination number and the nature of the electronic absorption band (f → f transition) of lanthanide(III) ion in their complexes are, respectively, (A) greater than 6 and sharp                            (B) 6 and broad (C) less than 6 and sharp                    (D) greater than 6 and broad Ans: greater than 6 and sharp

Q. Spectroscopic ground state term symbols of cobalt ions in [Co(H2O)6]2+ and [CoCl4]2–, respectively, are (A) 2T1g and 4A2                                                 (B) 4T1g and 4A2 (C) 4T2g and 4T1                                 (D) 2T1 and 4A1 Ans: 4T1g and 4A2

Q. The O2 coordinated to metal ion centres in oxy-myoglobin and oxy-hemocyanin exists, respectively, as (A) superoxide and peroxide (B) superoxide and superoxide (C) peroxide and peroxide (D) superoxide and oxygen Ans: superoxide and peroxide

Q. The symmetry label of valence p orbitals of a metal ion in an octahedral ligand field is (A) t1g  (B) t1u  (C) eg + a1g      (D) t2g Ans: t1u

Q. The lowest energy d → d transition of the complexes follow the order (A) [Cr(H2O)6]3+ < [Cr(NH3)6]3+ < [Cr(CN)6]3– (B) [Cr(CN)6]3– < [Cr(NH3)6]3+ < [Cr(H2O)6]3+ (C) [Cr(CN)6]3– < [Cr(H2O)6]3+ < [Cr(NH3)6]3+ (D) [Cr(NH3)6]3+ < [Cr(CN)6]3– < [Cr(H2O)6]3+ Ans: [Cr(H2O)6]3+ < [Cr(NH3)6]3+ < [Cr(CN)6]3–

Q. The water exchange rates for the complex ions follow the order (A) [V(H2O)6]2+ > [Co(H2O)6]2+ > [Cr(H2O)6]3+ (B) [Cr(H2O)6]3+ > [Co(H2O)6]2+ > [V(H2O)6]2+ (C) [Co(H2O)6]2+ > [Cr(H2O)6]3+ > [V(H2O)6]2+ (D) [Co(H2O)6]2+ > [V(H2O)6]2+ > [Cr(H2O)6]3+ Ans: [Co(H2O)6]2+ > [V(H2O)6]2+ > [Cr(H2O)6]3+

Q. The coordination geometries around the copper ion of plastocyanin (a blue-copper protein) in oxidized and reduced form, respectively, are (A) tetrahedral and square-planar (B) square-planar and tetrahedral (C) distorted tetrahedral for both (D) ideal tetrahedral for both Ans: distorted tetrahedral for both

Q. Based on Wade’s rule, the structure-type of [B5H8]– is (A) closo (B) nido (C) arachno (D) hypho Ans: nido

Q. According to Eyring transition state theory for a bimolecular reaction, the activated complex has (A) no vibrational degrees of freedom. (B) vibrational degrees of freedom but they never participate in product formation. (C) one high frequency vibration that leads to product formation. (D) one low frequency vibration that leads to product formation. Ans: one