Coordination Compounds Uses Flashcards
What forms the basis for detecting and estimating metal ions in qualitative and quantitative analysis?
The formation of coordination entities due to reactions between metal ions and ligands.
Name some examples of ligands commonly used in coordination compounds for chemical analysis.
EDTA, DMG (dimethylglyoxime), α–nitroso–β–naphthol, and cupron.
What type of ligands are particularly useful for the detection of metal ions?
Chelating ligands.
What is EDTA commonly used for in coordination chemistry?
EDTA is used as a reagent in both qualitative and quantitative analysis to detect and estimate metal ions.
Why do coordination compounds exhibit characteristic color reactions?
The formation of coordination entities between metal ions and ligands leads to characteristic color changes.
What is the full form of DMG, and what is it used for in coordination chemistry?
DMG stands for dimethylglyoxime. It is used as a reagent to detect specific metal ions, such as nickel.
What is the role of α-nitroso-β-naphthol in chemical analysis?
α-nitroso-β-naphthol acts as a ligand to form coordination compounds with metal ions, aiding in their detection and analysis.
What is meant by chelating ligands?
Chelating ligands are ligands that can form multiple bonds with a single metal ion, creating stable ring-like coordination entities.
What is a coordination entity in the context of chemical analysis?
A coordination entity is a complex formed when a central metal ion is surrounded by a set of ligands bonded through coordination bonds.
What is the significance of cupron in coordination chemistry?
Cupron is used as a ligand to detect and estimate metal ions through the formation of colored coordination compounds.
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How is the hardness of water commonly estimated?
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The hardness of water is estimated by simple titration with Na2EDTA
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Which ions in water form stable complexes with EDTA?
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Ca²⁺ (calcium) and Mg²⁺ (magnesium) ions form stable complexes with EDTA.
What allows for the selective estimation of calcium and magnesium ions in water hardness testing?
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The difference in the stability constants of the calcium and magnesium complexes allows for their selective estimation.
Why is Na2EDTA used in the titration method for determining water hardness?
ack:
Na2EDTA forms stable complexes with calcium and magnesium ions, making it ideal for titration and estimating their concentration in water.
What is the role of stability constants in the estimation of calcium and magnesium ions?
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The difference in stability constants of the calcium and magnesium complexes helps distinguish between the two ions during titration.
How are metals like gold and silver extracted through complex formation?
Gold and silver can be extracted through complex formation, where the metal ions form complexes with ligands, facilitating their separation from ores.
What complex does gold form during extraction using cyanide?
Gold forms the coordination entity [Au(CN)₂]⁻ in aqueous solution when combined with cyanide in the presence of oxygen and water.
What role does cyanide play in the extraction of gold?
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Cyanide forms a stable complex with gold ions, aiding in their dissolution and making it easier to separate gold from its ore.
How can gold be separated from its cyanide complex?
Gold can be separated in metallic form from the cyanide solution by adding zinc, which reduces the gold back to its metallic state.
What happens when zinc is added to the gold-cyanide solution during extraction?
Zinc reduces the gold from its complex, precipitating the gold as a solid metal.
What is the coordination entity formed when gold reacts with cyanide?
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The coordination entity formed is [Au(CN)₂]⁻.
How can metals be purified using coordination compounds?
Metals can be purified by first forming coordination compounds with them, and then decomposing the complex to yield the pure metal.
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What is an example of a metal that can be purified through coordination compound formation?
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An example is nickel, which can be purified by forming [Ni(CO)₄] and then decomposing it.
What is the coordination compound formed during the purification of impure nickel?
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The coordination compound formed is [Ni(CO)₄] (nickel carbonyl).
How is pure nickel obtained from its coordination compound [Ni(CO)₄]?
[Ni(CO)₄] is decomposed to yield pure nickel metal.
Why is nickel converted to [Ni(CO)₄] in the purification process?
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Nickel is converted to [Ni(CO)₄] to separate it from impurities and then decompose the compound to obtain the pure metal.
How are coordination compounds important in biological systems?
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Coordination compounds play a key role in biological systems, such as in enzymes, pigments, and other essential molecules that involve metal ions.
What is the coordination compound responsible for photosynthesis?
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The pigment chlorophyll, responsible for photosynthesis, is a coordination compound of magnesium.
What is haemoglobin, and how is it related to coordination chemistry?
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Haemoglobin is the red pigment in blood that acts as an oxygen carrier, and it is a coordination compound of iron.
Which coordination compound is important for treating pernicious anaemia?
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Vitamin B12 (cyanocobalamin), which is a coordination compound of cobalt, is important in the treatment of pernicious anaemia.
What role do coordination compounds play in enzymes like carboxypeptidase and carbonic anhydrase?
Carboxypeptidase A and carbonic anhydrase are enzymes that function as biological catalysts, and their activity relies on coordinated metal ion
Which metal ion is found in chlorophyll, the pigment responsible for photosynthesis?
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Magnesium (Mg²⁺) is the metal ion in chlorophyll
What metal ion is central to the coordination complex of haemoglobin?
Back:
Iron (Fe²⁺ or Fe³⁺) is central to the coordination complex of haemoglobin
What is the role of cobalt in Vitamin B12?
Cobalt is the central metal ion in Vitamin B12 (cyanocobalamin), which plays a key role in preventing pernicious anaemia.
How are coordination compounds used as catalysts in industrial processes?
Coordination compounds are used as catalysts to speed up chemical reactions, such as in the hydrogenation of alkenes or electroplating processes.
What is the Wilkinson catalyst, and what is its role in industrial chemistry?
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The Wilkinson catalyst, [(Ph₃P)₃RhCl], is a rhodium complex used as a catalyst for the hydrogenation of alkenes
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How does the Wilkinson catalyst facilitate the hydrogenation of alkenes?
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The Wilkinson catalyst facilitates the hydrogenation of alkenes by promoting the addition of hydrogen to the double bond in alkenes
Why are complexes like [Ag(CN)₂]⁻ and [Au(CN)₂]⁻ used in electroplating?
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These complexes are used in electroplating because they allow for smoother and more even deposition of silver and gold than simple metal ions.
What is the benefit of using [Ag(CN)₂]⁻ and [Au(CN)₂]⁻ complexes for electroplating?
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The complexes result in a more uniform and smooth layer of metal being electroplated onto articles compared to using simple metal ion
What metal is used in the Wilkinson catalyst for hydrogenation reactions?
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Rhodium (Rh) is the metal used in the Wilkinson catalys
What role do coordination compounds play in black and white photography?
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Coordination compounds are used in the fixing process to dissolve undecomposed silver bromide (AgBr) and form a complex ion, allowing for the permanent development of the image
What is the complex ion formed during the fixing process in black and white photography?
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The complex ion formed is [Ag(S₂O₃)₂]³⁻, where silver ions are coordinated with thiosulfate ion
What is the function of the hypo solution in the photographic development process?
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The hypo solution, which contains sodium thiosulfate (Na₂S₂O₃), dissolves undecomposed silver bromide (AgBr) from the film and forms a soluble coordination complex.
Why is the [Ag(S₂O₃)₂]³⁻ complex ion important in black and white photography?
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The [Ag(S₂O₃)₂]³⁻ complex makes the silver bromide (AgBr) soluble, allowing it to be washed away, thus fixing the developed image on the film
What is silver bromide (AgBr), and why is it important in photography?
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Silver bromide (AgBr) is a light-sensitive compound used in photographic films and papers, where it reacts to light during exposure to form an imag
What is the role of sodium thiosulfate (Na₂S₂O₃) in the fixing process?
Sodium thiosulfate (Na₂S₂O₃) acts as a ligand, binding to silver ions in the undecomposed AgBr and forming the complex [Ag(S₂O₃)₂]³⁻, which is soluble and can be washed away
What is chelate therapy, and how is it used in medicinal chemistry?
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Chelate therapy involves the use of chelating agents to form coordination complexes with metals, helping to remove toxic metal ions from plant and animal systems or treat metal poisoning
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Which chelating agents are used to remove excess copper and iron from the body?
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D-penicillamine and desferrioxamine B are used to remove excess copper and iron by forming coordination compounds with these metals
What role do coordination compounds of platinum play in medicine?
Coordination compounds of platinum, such as cis-platin, are used as chemotherapy agents because they effectively inhibit the growth of tumors.
What is cis-platin, and why is it important in cancer treatment?
Cis-platin is a platinum-based coordination compound used in chemotherapy to treat various cancers by interfering with DNA replication in tumor cells.
How does EDTA help in the treatment of lead poisoning?
EDTA forms a stable coordination complex with lead ions, allowing for their removal from the body and reducing the toxicity caused by lead poisoning.
How do chelating agents like D-penicillamine and desferrioxamine B work to remove toxic metals?
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These chelating agents bind to excess metal ions like copper and iron, forming stable coordination complexes that can be excreted from the body, reducing toxicity.
stablity of complex refers to
degree of association between the 2 species
stablity constant=
beta
beta=
Beta of Cuprammonioum
[cu(NH3)4 +2]/ [Cu+2][NH3]
instablity constant or dissociation constant [K] of coordination compound is=
Reciprocal of formation constant [Beta]
K=
1/[beta]
Beta 4 for complex is 2.1 x 10^13 overall complex dissociation equilibrium constant for
Cu(NH3)4 2+
4.76x10^-14
carbonyl compounds
