Which statement is correct about this reaction?
[Co(NH₃)₆]²⁺ + 3H₂NCH₂CH₂NH₂ → [Co(HNCH₂CH₂NH₂)₃]²⁺ + 6NH₃ - AQA - A-Level Chemistry - Question 26 - 2018 - Paper 3
Question 26
Which statement is correct about this reaction?
[Co(NH₃)₆]²⁺ + 3H₂NCH₂CH₂NH₂ → [Co(HNCH₂CH₂NH₂)₃]²⁺ + 6NH₃
Worked Solution & Example Answer:Which statement is correct about this reaction?
[Co(NH₃)₆]²⁺ + 3H₂NCH₂CH₂NH₂ → [Co(HNCH₂CH₂NH₂)₃]²⁺ + 6NH₃ - AQA - A-Level Chemistry - Question 26 - 2018 - Paper 3
Step 1
A. The co-ordination number of cobalt decreases.
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Answer
In this reaction, cobalt transitions from a hexammine complex to a complex with three bidentate ligands. The co-ordination number of cobalt decreases from 6 to 3.
Step 2
B. The enthalpy change is large and positive.
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Answer
The enthalpy change in reactions involving complex formation can vary, and it is not guaranteed that it will be large and positive in this case.
Step 3
C. The entropy change is large and positive.
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Answer
The formation of the new complex involves the release of ammonia molecules, which enhances disorder. Therefore, the entropy change is indeed large and positive.
Step 4
D. The shape of the complex changes from octahedral.
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Answer
The original complex has an octahedral geometry, but the product complex has a different geometry due to the different ligands, indicating that the shape changes.
![Which-statement-is-correct-about-this-reaction?--[Co(NH₃)₆]²⁺-+-3H₂NCH₂CH₂NH₂-→-[Co(HNCH₂CH₂NH₂)₃]²⁺-+-6NH₃-AQA-A-Level Chemistry-Question 26-2018-Paper 3.png](https://cdn.simplestudy.cloud/assets/backend/uploads/question/Question_26_2018_Chemistry_P3.jpg)
