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When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?
- a)[CoCl4]2-
- b)[CoCl6]3-
- c)[CoCl6]4-
- d)[Co(H2O)6]2+
Correct answer is option 'A'. Can you explain this answer?
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Verified Answer
When concentrated HCl is added to an aqueous solution of CoCl2, its co...
A queous solution of CoCl2 contains [Co(H2O)6]2+ which is pinkish in colour so option (d) is incorrect.
Reduction potential of Co3+ → Co2+ is high so option(b) is incorrect. Co2+ does not oxidises easily to Co3+.
It is general case that symmetrical substituted octahedral complexes are less deeper in colour than tetrahedral complexes.
So [CoCI4]2- is deep blue in colour.
Reduction potential of Co3+ → Co2+ is high so option(b) is incorrect. Co2+ does not oxidises easily to Co3+.
It is general case that symmetrical substituted octahedral complexes are less deeper in colour than tetrahedral complexes.
So [CoCI4]2- is deep blue in colour.
Most Upvoted Answer
When concentrated HCl is added to an aqueous solution of CoCl2, its co...
Answer:
When concentrated HCl is added to an aqueous solution of CoCl2, which contains Co2+ ions, the color changes from reddish pink to deep blue. This change in color is due to the formation of a complex ion.
Complex Ion Formation:
The Co2+ ions in the aqueous solution have a pink color due to the presence of water molecules coordinated to the central cobalt ion. When HCl is added, it provides chloride ions (Cl-) which can coordinate with the Co2+ ions and form complex ions.
Formation of [CoCl4]2-:
The addition of chloride ions leads to the formation of the complex ion [CoCl4]2-. This complex ion has a deep blue color. The coordination of four chloride ions with the central cobalt ion results in the formation of a tetrahedral complex. The presence of these chloride ions alters the electronic structure of the cobalt ion, leading to a change in the absorption spectrum of light. As a result, the color of the solution changes from reddish pink to deep blue.
Explanation of other options:
- [CoCl6]3-: This complex ion would have a coordination number of 6, but it is not formed when HCl is added to the solution.
- [CoCl6]4-: This complex ion would have a coordination number of 6, but it is not formed when HCl is added to the solution.
- [Co(H2O)6]2+: This complex ion is already present in the original solution and is responsible for the initial reddish pink color. It does not change to deep blue upon the addition of HCl.
Therefore, the correct answer is option A, [CoCl4]2-, which forms a deep blue complex ion when HCl is added to the aqueous solution of CoCl2.
When concentrated HCl is added to an aqueous solution of CoCl2, which contains Co2+ ions, the color changes from reddish pink to deep blue. This change in color is due to the formation of a complex ion.
Complex Ion Formation:
The Co2+ ions in the aqueous solution have a pink color due to the presence of water molecules coordinated to the central cobalt ion. When HCl is added, it provides chloride ions (Cl-) which can coordinate with the Co2+ ions and form complex ions.
Formation of [CoCl4]2-:
The addition of chloride ions leads to the formation of the complex ion [CoCl4]2-. This complex ion has a deep blue color. The coordination of four chloride ions with the central cobalt ion results in the formation of a tetrahedral complex. The presence of these chloride ions alters the electronic structure of the cobalt ion, leading to a change in the absorption spectrum of light. As a result, the color of the solution changes from reddish pink to deep blue.
Explanation of other options:
- [CoCl6]3-: This complex ion would have a coordination number of 6, but it is not formed when HCl is added to the solution.
- [CoCl6]4-: This complex ion would have a coordination number of 6, but it is not formed when HCl is added to the solution.
- [Co(H2O)6]2+: This complex ion is already present in the original solution and is responsible for the initial reddish pink color. It does not change to deep blue upon the addition of HCl.
Therefore, the correct answer is option A, [CoCl4]2-, which forms a deep blue complex ion when HCl is added to the aqueous solution of CoCl2.
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When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer?
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When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer?.
When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer?.
Solutions for When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for NEET.
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When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer?, a detailed solution for When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of When concentrated HCl is added to an aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives deep blue colour in this reaction?a)[CoCl4]2-b)[CoCl6]3-c)[CoCl6]4-d)[Co(H2O)6]2+Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
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