The functional group which is found in an amino acid are COOH and NH₃ (amine group). So every amino acid has a central carbon with a H,R group (varies for each amino acid), a carboxylic group and an amine group. These groups are joined to a single (aliphatic) carbon. The carbon directly attached to a carboxyl group is the alpha position, so the amino acids in proteins are all alpha-amino acids.

Ammonia acts as a ligand as it donates its lone pair of electrons to Cu²⁺ ions to form [Cu(NH₃)₄]²⁺ complex. This is possible in basic medium. In an acidic medium, the lone pair of electrons present on ammonia is donated to proton to form ammonium ion which is not a ligand and cannot form a complex with Cu²⁺ ions.

its an oxidation reaction.

Pyridinium chlorochromate is a mild oxidising agent that oxidises primary alcohol to aldehydes and secondary alcohols to ketones. It does not affect any other functional group and therefore has high selectivity for oxidation of alcohols. Whereas acidic permanganate, acidic dichromate, chromic anhydride in glacial acetic acid are strong oxidising agents and can do further oxidation to carboxylic acid.

The most suitable reagent for RCH₂OH→RCHO is pyridinium chlorochromate (PCC).

As AgNO₃ is added to the solution, KCl will be displaced according to the following reaction.

AgNO₃(aq)+KCl(aq)⟶AgCl(s)+KNO₃(aq)

For every mole of KCl displaced from solution, one mole of KNO₃ comes in solution resulting in almost constant conductivity. As the endpoint is reached, added AgNO₃ remain in solution increasing ionic concentration, thus conductivity increases.

Tetrabasic acid means acids having 4− replaceable hydrogen atoms.

Pyro phosphoric acid ⟶H₄P₂O₇

Ortho phosphoric acid ⟶H₃PO₄

Hypo phosphorus acid ⟶H₃PO₂ 

Meta phosphoric acid ⟶(HPO₃)_n

Here, pyro phosphoric acid, H₄P₂O₇ have 4 removable H⁺ ions, thus it is a tetrabasic.

Bismuth nitrate, Bi(NO₃)₃, reacts with KI to give a black precipitate of Bil₃, which on the addition of an excess of KI, dissolved to give an orange colour solution of K[Bil₄] complex salt.

Octahedral Co(NH₃)₄Br₂Cl shows ionisation and geometrical isomerism.

In ionisation isomerism ligands shown in the coordination sphere and the anions present outside the coordination, sphere are exchanged with each other as follows:

The coordination number of the central atom (cobalt) is six and the shape is octahedral, so it shows the following geometrical isomers.

The reaction occurring in two steps has two activation energy peaks. The first step being fast needs less activation energy. The second step being slow needs more activation energy. Therefore, the second peak will be higher than the first.

The complex [Cr(NH₃)₆]Cl₃ involved d²sp³ hybridization as it involves (n−1)d orbitals for hybridization. It is an inner orbital complex.

The d-orbital involved in hybridization belongs to the penultimate shell due to the presence of a strong ligand.

In (MnO₄)⁻,CrO₂Cl₂ oxidation states of Mn and Cr are +7 and +6 respectively.

[NiCl₄]²⁻,[COCl₄]⁻ oxidation states of Ni and Co are +2 and +3 respectively.

In [Fe(CN)₆]³⁻,[CO(CN)₆]³⁻ oxidation states of Fe and Co are +3 and +3 respectively.

In MnO₂ and FeCl₃ oxidation states of Mn and Fe are +4 and +3 respectively.