PYQs Homework Notes Mocks Board Daily Homework JEE Mains Chemistry Question type Identify or count the paramagnetic or diamagnetic complexes in a list This type of question, asked 10 times: 2021 Paper 14, 28 Jun 2022, 26 Jul 2022, 25 Jan 2023, 8 Apr 2023, 10 Apr 2023, 3 Apr 2025, 7 Apr 2025, 24 Jan 2026 S1, 8 Apr 2026 S2. All 11 questions below, oldest first.
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Question 1 2021 Paper 14
32 Which of the following complexes show attraction in an external magnetic field?
A. C o ( C N ) 6 3 − Co(CN)_{6}\ ^{3 -} C o ( C N ) 6 3 − B. N i ( C O ) 4 Ni(CO)_{4} N i ( C O ) 4 C. N i ( C N ) 4 2 − Ni(CN)4^{2 -} N i ( C N ) 4 2 − D. F e ( H 2 O ) 6 3 + Fe\left( H_{2}O \right)_{6}\ ^{3 +} F e ( H 2 O ) 6 3 + Tap an option to check your answer.
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Question 2 28 Jun 2022
146 [ F e ( C N ) 6 ] 4 − \left\lbrack Fe(CN)_{6} \right\rbrack^{4 -} [ F e ( C N ) 6 ] 4 − [ F e ( C N ) 6 ] 3 − \left\lbrack Fe(CN)_{6} \right\rbrack^{3 -} [ F e ( C N ) 6 ] 3 − [ T i ( C N ) 6 ] 3 − \left\lbrack Ti(CN)_{6} \right\rbrack^{3 -} [ T i ( C N ) 6 ] 3 − [ N i ( C N ) 4 ] 2 − \left\lbrack Ni(CN)_{4} \right\rbrack^{2 -} [ N i ( C N ) 4 ] 2 − [ C o ( C N ) 6 ] 3 − \left\lbrack Co(CN)_{6} \right\rbrack^{3 -} [ C o ( C N ) 6 ] 3 − Among the given complexes, number of paramagnetic complexes is
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Question 3 26 Jul 2022
131 The metal complex that is diamagnetic is (Atomic number: F e , 26 Fe,26 F e , 26 ; C u , 29 Cu,29 C u , 29 ) A. K 3 [ C u ( C N ) 4 ] K_{3}\left\lbrack Cu(CN)_{4} \right\rbrack K 3 [ C u ( C N ) 4 ] B. K 2 [ C u ( C N ) 4 ] K_{2}\left\lbrack Cu(CN)_{4} \right\rbrack K 2 [ C u ( C N ) 4 ] C. K 3 [ F e ( C N ) 4 ] K_{3}\left\lbrack Fe(CN)_{4} \right\rbrack K 3 [ F e ( C N ) 4 ] D. K 4 [ F e C l 6 ] K_{4}\left\lbrack {FeCl}_{6} \right\rbrack K 4 [ F e C l 6 ] Tap an option to check your answer.
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Question 4 25 Jan 2023
57 The number of paramagnetic species from the following is [ N i ( C N ) 4 ] 2 − , [ N i ( C O ) 4 ] , [ N i C l 4 ] 2 − [ F e ( C N ) 6 ] 4 − , [ C u ( N H 3 ) 4 ] 2 + [ F e ( C N ) 6 ] 3 − and [ F e ( H 2 O ) 6 ] 2 + \begin{matrix} & \left\lbrack Ni(CN)_{4} \right\rbrack^{2 -},\left\lbrack Ni(CO)_{4} \right\rbrack,\left\lbrack NiCl_{4} \right\rbrack^{2 -} \\ & \left\lbrack Fe(CN)_{6} \right\rbrack^{4 -},\left\lbrack Cu\left( NH_{3} \right)_{4} \right\rbrack^{2 +} \\ & \left\lbrack Fe(CN)_{6} \right\rbrack^{3 -}\text{~and~}\left\lbrack Fe\left( H_{2}O \right)_{6} \right\rbrack^{2 +} \end{matrix} [ N i ( C N ) 4 ] 2 − , [ N i ( C O ) 4 ] , [ N i C l 4 ] 2 − [ F e ( C N ) 6 ] 4 − , [ C u ( N H 3 ) 4 ] 2 + [ F e ( C N ) 6 ] 3 − and [ F e ( H 2 O ) 6 ] 2 +
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Question 5 8 Apr 2023
39 Which of the following complex is octahedral, diamagnetic and the most stable?
A. N a 3 [ C o C l 6 ] {Na}_{3}\left\lbrack {CoCl}_{6} \right\rbrack N a 3 [ C o C l 6 ] B. [ N i ( N H 3 ) 6 ] C l 2 \left\lbrack Ni\left( {NH}_{3} \right)_{6} \right\rbrack{Cl}_{2} [ N i ( N H 3 ) 6 ] C l 2 C. K 3 [ C o ( C N ) 6 ] K_{3}\left\lbrack Co(CN)_{6} \right\rbrack K 3 [ C o ( C N ) 6 ] D. [ C o ( H 2 O ) 6 ] C l 2 \left\lbrack Co\left( H_{2}O \right)_{6} \right\rbrack{Cl}_{2} [ C o ( H 2 O ) 6 ] C l 2 Tap an option to check your answer.
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Question 6 10 Apr 2023
42 The octahedral diamagnetic low spin complex among the following is
A. [ N i C l 4 ] 2 − \left\lbrack {NiCl}_{4} \right\rbrack^{2 -} [ N i C l 4 ] 2 − B. [ C o C l 6 ] 3 − \left\lbrack {CoCl}_{6} \right\rbrack^{3 -} [ C o C l 6 ] 3 − C. [ C o F 6 ] 3 − \left\lbrack {CoF}_{6} \right\rbrack^{3 -} [ C o F 6 ] 3 − D. [ C o ( N H 3 ) 6 ] 3 + \left\lbrack Co\left( {NH}_{3} \right)_{6} \right\rbrack^{3 +} [ C o ( N H 3 ) 6 ] 3 + Tap an option to check your answer.
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Question 7 3 Apr 2025
110 Identify the diamagnetic octahedral complex ions from below ; A. [ M n ( C N ) 6 ] 3 − \left\lbrack Mn(CN)_{6} \right\rbrack^{3 -} [ M n ( C N ) 6 ] 3 − B. [ C o ( N H 3 ) 6 ] 3 + \left\lbrack Co\left( {NH}_{3} \right)_{6} \right\rbrack^{3 +} [ C o ( N H 3 ) 6 ] 3 + C. [ F e ( C N ) 6 ] 4 − \left\lbrack Fe(CN)_{6} \right\rbrack^{4 -} [ F e ( C N ) 6 ] 4 − D. [ C o ( H 2 O ) 3 F 3 ] \left\lbrack Co\left( H_{2}O \right)_{3}{\text{ }F}_{3} \right\rbrack [ C o ( H 2 O ) 3 F 3 ] Choose the correct answer from the options given below : A. B and D Only
B. A and D Only
C. A and C Only
D. B and C Only
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Question 8 7 Apr 2025
50 The number of paramagnetic complex among [ F e F 6 ] 3 − , [ F e ( C N ) 6 ] 3 − , [ M n ( C N ) 6 ] 3 − , [ C o ( C 2 O 4 ) 3 ] 3 − \left\lbrack {FeF}_{6} \right\rbrack^{3 -},\left\lbrack Fe(CN)_{6} \right\rbrack^{3 -},\left\lbrack Mn(CN)_{6} \right\rbrack^{3 -},\left\lbrack Co\left( C_{2}O_{4} \right)_{3} \right\rbrack^{3 -} [ F e F 6 ] 3 − , [ F e ( C N ) 6 ] 3 − , [ M n ( C N ) 6 ] 3 − , [ C o ( C 2 O 4 ) 3 ] 3 − , [ M n C l 6 ] 3 − \left\lbrack {MnCl}_{6} \right\rbrack^{3 -} [ M n C l 6 ] 3 − and [ C o F 6 ] 3 − \left\lbrack {CoF}_{6} \right\rbrack^{3 -} [ C o F 6 ] 3 − , which involved d 2 s p 3 d^{2}{sp}^{3} d 2 s p 3 hybridization is ____
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Question 9 7 Apr 2025
124 The number of paramagnetic metal complex species among [ C o ( N H 3 ) 6 ] 3 + , [ C o ( C 2 O 4 ) 3 ] 3 − \left\lbrack Co\left( {NH}_{3} \right)_{6} \right\rbrack^{3 +},\ \left\lbrack Co\left( C_{2}O_{4} \right)_{3} \right\rbrack^{3 -} [ C o ( N H 3 ) 6 ] 3 + , [ C o ( C 2 O 4 ) 3 ] 3 − , [ M n C l 6 ] 3 − , [ M n ( C N ) 6 ] 3 − , [ C o F 6 ] 3 − , [ F e ( C N ) 6 ] 3 − \left\lbrack {MnCl}_{6} \right\rbrack^{3 -},\left\lbrack Mn(CN)_{6} \right\rbrack^{3 -},\left\lbrack {CoF}_{6} \right\rbrack^{3 -},\left\lbrack Fe(CN)_{6} \right\rbrack^{3 -} [ M n C l 6 ] 3 − , [ M n ( C N ) 6 ] 3 − , [ C o F 6 ] 3 − , [ F e ( C N ) 6 ] 3 − and [ F e F 6 ] 3 − \left\lbrack {FeF}_{6} \right\rbrack^{3 -} [ F e F 6 ] 3 − with same number of unpaired electrons is.
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Question 10 24 Jan 2026 S1
34 Given below are two statements Statements-I : The number of paramagnetic species among [ C o F 6 ] 3 − , [ T i F 6 ] 3 − , V 2 O 5 \left\lbrack {CoF}_{6} \right\rbrack^{3 -},\ \left\lbrack {TiF}_{6} \right\rbrack^{3 -},\ V_{2}O_{5} [ C o F 6 ] 3 − , [ T i F 6 ] 3 − , V 2 O 5 and [ F e ( C N ) 6 ] 3 − \left\lbrack Fe(CN)_{6} \right\rbrack^{3 -} [ F e ( C N ) 6 ] 3 − is 3 . Statement-II : K 4 [ F e ( C N ) 6 ] < K 3 [ F e ( C N ) 6 ] < [ F e ( H 2 O ) 6 ] S O 4 ⋅ H 2 O < [ F e ( H 2 O ) 6 ] C l 3 K_{4}\left\lbrack Fe(CN)_{6} \right\rbrack < K_{3}\left\lbrack Fe(CN)_{6} \right\rbrack < \left\lbrack Fe\left( H_{2}O \right)_{6} \right\rbrack{SO}_{4} \cdot H_{2}O < \left\lbrack Fe\left( H_{2}O \right)_{6} \right\rbrack{Cl}_{3} K 4 [ F e ( C N ) 6 ] < K 3 [ F e ( C N ) 6 ] < [ F e ( H 2 O ) 6 ] S O 4 ⋅ H 2 O < [ F e ( H 2 O ) 6 ] C l 3 is the correct order in terms of number of unpaired electron(s) in the complexes. In the light of the above statements, choose the correct answer from the options given below. A. Both statement-I and statement-II are true
B. Both statement-I and statement-II are false
C. Statement-I is true but statement-II is false
D. Statement-I is false but statement-II is true
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Question 11 8 Apr 2026 S2
46 Number of paramagnetic complexes among the following is _ _ _ _ \_\_\_\_ ____ . [ M n B r 4 ] 2 − \left\lbrack {MnBr}_{4} \right\rbrack^{2 -} [ M n B r 4 ] 2 − , [ N i C l 4 ] 2 − \left\lbrack {NiCl}_{4} \right\rbrack^{2 -} [ N i C l 4 ] 2 − , [ N i ( C N ) 4 ] 2 − \left\lbrack Ni(CN)_{4} \right\rbrack^{2 -} [ N i ( C N ) 4 ] 2 − , [ N i ( C O ) 4 ] \left\lbrack Ni(CO)_{4} \right\rbrack [ N i ( C O ) 4 ] , [ C o F 6 ] 3 − \left\lbrack {CoF}_{6} \right\rbrack^{3 -} [ C o F 6 ] 3 − , [ F e ( C N ) 6 ] 4 − , [ M n ( C N ) 6 ] 3 − , [ T i ( C N ) 6 ] 3 − \lbrack Fe(CN)_{6}\rbrack^{4 -},\ \left\lbrack Mn(CN)_{6} \right\rbrack^{3 -},\ \left\lbrack Ti(CN)_{6} \right\rbrack^{3 -} [ F e ( C N ) 6 ] 4 − , [ M n ( C N ) 6 ] 3 − , [ T i ( C N ) 6 ] 3 − , [ C u ( H 2 O ) 6 ] 2 + , [ C o ( C 2 O 4 ) 3 ] 3 − \left\lbrack Cu\left( H_{2}O \right)_{6} \right\rbrack^{2 +},\left\lbrack Co\left( C_{2}O_{4} \right)_{3} \right\rbrack^{3 -} [ C u ( H 2 O ) 6 ] 2 + , [ C o ( C 2 O 4 ) 3 ] 3 −
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