Complexation and Precipitation Titrimetry

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What is the coordination number of the metal-ion M in Curve A?

Five
Six
Four (correct)
Three

What is the type of ligand that forms a complex with metal-ion M in Curve C?

Bidentate
Tetradentate
Hexadentate
Unidentate (correct)

What is the number of potential sites for bonding a metal ion in EDTA?

Four
Five
Six (correct)
Eight

What is the ratio of EDTA to metal ions in a reaction?

1:1 (A) Signup and view all the answers

Why is an auxiliary complexing agent needed in some EDTA titrations?

To keep the cation in solution (C) Signup and view all the answers

What is another use of EDTA besides being a titrant?

As a food preservative (B) Signup and view all the answers

What type of reagents are used in Complex-Formation Titrations?

Organic compounds that contain several electrondonor groups (A) Signup and view all the answers

What is the typical coordination number for most metal ions?

Two, four, and six (A) Signup and view all the answers

What is the term for the species formed as a result of coordination?

Coordination compound (C) Signup and view all the answers

What is the advantage of using multidentate ligands over unidentate ligands?

They generally react more completely with cations and provide sharper end points (A) Signup and view all the answers

What is the term for a ligand with two donor groups?

Bidentate (A) Signup and view all the answers

What is the term for a process where a metal ion coordinates with two or more donor groups of a single ligand to form a five- or six-membered heterocyclic ring?

Chelation (C) Signup and view all the answers

What is the primary purpose of using a medium with high concentrations of ammonia and ammonium chloride in zinc(II) titration?

To reduce the interference of other metal ions (D) Signup and view all the answers

What is the characteristic of Eriochrome Black T that makes it useful as an indicator in EDTA titrations?

It forms red complexes with more than two dozen metal ions (C) Signup and view all the answers

What is the definition of water hardness in terms of the concentration of calcium and magnesium ions?

It is the total concentration of calcium and magnesium ions expressed as the concentration of calcium carbonate (C) Signup and view all the answers

What type of reaction is the basis of precipitation titrations?

Reactions that yield ionic compounds of limited solubility (C) Signup and view all the answers

What is the primary use of silver nitrate in titrations?

To determine the concentration of halogens and halogenlike anions (A) Signup and view all the answers

What is the characteristic of indicators used in argentometric titrations?

They respond to changes in the concentration of silver ions (B) Signup and view all the answers

What is the typical plot of a titration curve for precipitation reactions?

pAg versus volume of the silver reagent (C) Signup and view all the answers

What is the effect of increasing the solubility product on the sharpness of the end point?

The end point becomes less sharp (B) Signup and view all the answers

What is the role of iron(III) in the Volhard method?

It serves as an indicator (D) Signup and view all the answers

What is the result of adding a slight excess of thiocyanate ion to the solution in the Volhard method?

The solution turns red (A) Signup and view all the answers

What is the most important application of the Volhard method?

Indirect determination of halide ions (D) Signup and view all the answers

What is the reason why silver chloride is not used in the Volhard method?

Silver chloride is more soluble than silver thiocyanate (D) Signup and view all the answers

Coordination Number

The number of donor atoms directly attached to a central metal atom.

Ligand

A molecule or ion that can donate a pair of electrons to form a coordinate covalent bond with a metal ion.