AQA A Level Chemistry - Tetrahedral Complexes & Tollens' Test

What are the ligands commonly found in transition metal tetrahedral complexes?

• Bidentate ligands such as ethylenediamine or the oxalate ion.

• The ligands commonly found in transition metal tetrahedral complexes are large anions such as chloride (Cl^-).

• Chelating agents such as EDTA (Ethylenediaminetetraacetic acid)

• Small, neutral molecules such as water (H₂O) and ammonia (NH₃)

State the conditions required for the Tollens' silver mirror test.

• A solution of silver nitrate, ammonia, and a ketone compound.

• A solution of silver nitrate, sodium hydroxide, ammonia, and an aldehyde compound (including reducing sugars).

• A solution of silver sulfate, ammonia, and an aldehyde compound.

• A solution of silver chloride, ammonia, and an aldehyde compound.

Which is an application of the Tollens' silver mirror test in organic chemistry.

• To determine the acidity of organic compounds.

• To identify the presence of halogens in organic compounds.

• To distinguish between aldehydes and ketones in organic chemistry.

• To measure the boiling point of organic compounds.

Describe the shape of the diaminesilver(i) hydroxide complex.

• Octahedral.

• Linear

• Tetrahedral

• Square Planar

Which describes the d orbital splitting in tetrahedral complexes.

• d_^x2-y2 & d_Z2 high energy, d_xy, d_xz, d_yz low energy. The energy difference between the two sets is denoted as Δ_tet.

• All d orbitals are degenerate

• In tetrahedral complexes, the d orbitals split into three sets: the lower energy set (t1), the middle energy set (t2), and the higher energy set (t3).

• d_^x2-y2 & d_Z2 low energy, d_xy, d_xz, d_yz high energy. The energy difference between the two sets is denoted as Δ_oct.

How do ligands affect the properties of transition metal tetrahedral complexes?

• Ligands can affect the properties of transition metal tetrahedral complexes by influencing the geometry, stability, and reactivity of the complex.

• Ligands decrease the stability of transition metal tetrahedral complexes

• Ligands have no effect on the properties of transition metal tetrahedral complexes

• Ligands only affect the color of transition metal tetrahedral complexes

What is the purpose of adding ammonia in the Tollens' silver mirror test?

• To neutralize the acidic silver nitrate solution.

• To speed up the reduction of silver(I) ions and the reducing sugar.

• To reverse the precipitation of silver oxide and maintain the alkaline pH required for the reaction.

• To oxidise the silver metal atoms to allow them to redissolve.

Explain the role of silver nitrate in the Tollens' silver mirror test.

• Silver nitrate is used as a reducing agent to reduce the aldehyde.

• To neutralize the acidic nature of the ammonical solution.

• To provide the required color to the final solution.

• As a source of silver ions that are reduced by the aldehyde functional group in the presence of a base.

Discuss the significance of the Tollens' silver mirror test in qualitative analysis.

• Tollen's reagent reacts with alcohols to produce a silver mirror

• The Tollen's silver mirror test is used to identify halogens in organic compounds

• To distinguish between aldehydes and ketones.

• The Tollen's silver mirror test is used to differentiate between acids and bases

What is the role of sodium hydroxide in the Tollen's silver mirror test?

• Sodium hydroxide is used to create an alkaline environment, which helps to facilitate the reduction of silver ions to form a silver mirror on the inner surface of the test tube.

• Sodium hydroxide is used to increase the acidity of the solution

• Sodium hydroxide is used to speed up the reaction between silver ions and the test tube

• Sodium hydroxide is added to prevent the formation of a silver mirror