All those carbohydrates which contain a free aldehyde or Ketonic group and reduce Fehling's solution and Tollen's reagent are referred as a reducing Sugar. Examples of reducing sugar is galactose, glucose, glyceraldehyde, fructose, ribose, and xylose.

Vitamin A is essential to us because its deficiency causes xerophthalmia (hardening of cornea of eye) and night blindness.
Sources: Fish liver oil, carrots, butter, and milk.
Vitamin C. Vitamin C is essential to us because its deficiency causes scurvy (bleeding gums) and pyorrhea (loosening and bleeding of teeth).
Sources: Citrous fruits; arnIa, green leafy vegetables.

In both the complexes, Fe is in +2 state with the configuration 3d⁶, i.e., it has four unpaired electrons. As the ligands H₂O and CN^- possess different crystal field splitting energy, they absorb different components of the visible light (VIBGYOR) for d - d transition. Hence, the transmitted colours are different.

(a) Biological processes: Chlorophyll contains Mg, which is used in photosynthesis. Haemoglobin contains Fe, which acts as oxygen carrier. Vitamin-B₁₂ contain cobalt which is used to preven anaemia.
(b) Analytical chemistry:
(i) Ni²⁺ is detected by using DMG (dimethylglyoxime)
(ii) EDTA is used for sofening of hard water.
(c) Medicinal chemistry: cis-Platin is used as anticancer agent.
(d) Metallurgical operation: Cyanide complexes are used in extraction of Ag and Au.

(a) [Co(NH₃)₄CI(NO₂))CI = Tetraaminechloridoinitro cobalt(III) chloride
(b) [Ni(NH₃)₆]Cl₂ = Hexaaminenickel(II) chloride
(c) K₃[Cr(C₂O₄)₃] = Potassiumtrioxalatochromate (III)
(d) [Co(en)₂Br₂]⁺ = Dibromido bis (ethylenediamine)cobalt (III)ion

(i) Write the function ofthe follow Hydrolysis of cane sugar. 
(ii) Urease Decomposition of urea into NH₃ and CO₂.
(iii) Maltase Hydrolysis of maltose into glucose

(i) D-glucose and D-galactose.
(ii) Since, vitamin C is a water soluble vitamin, it is excreted out through urine, hence cannot be stored.
(iii) Nucleoside A unit formed by the attachment of a base to 1' position of sugar is known as nucleoside.

Nucleotide When nucleoside is linked to phosphoric acid at 5' position of sugar moiety, a nucleotide is obtained. They are joined together by phosphodiester linkage between 5' and 3' carbon atoms of the pentose sugar.

In [Co(NH ₃)₆]³⁺, Co is in +3 state with the configuration 3d⁶. In the presence of NH ₃, 3d electrons pair up leaving two d-orbitals empty. Hence, the hybridisation is d²sp forming an inner orbital complex. In [Ni(NH ³ forming an inner orbital complex. In [Ni(NH ₃)₆]²⁺, Ni is in +2 state with the configuration 3d.8. In presence of NH₃, the 3d electrons do not pair up. The hybridization involved is sp³d² forming an outer orbital complex.

Each strand consist of 4 bases which are Adenine, Guanine, Thymine and Cytosine.
These complementary bases are the following:
Adenine (A) ⇔ Thymine (T)
Cytosine (C) ⇔ Guanine  (G)
⇔ This symbol represents that both the left and right hand side bases are complementary to each other.
The two strands are internally connected by hydrogen bonding between complementary bases. The two strands of DNA are not identical because their sequence of bases has to be complementary to each other. Ex- If one sequence is ATCG the other has to be TAGC.

(i) [Fe(H₂O)₆]²⁺; Fe(26): [Ar]4s²3d⁶
Fe²⁺: [Ar]4s⁰ 3d⁶
H₂O is weak field ligand, does not cause pairing of electrons.
It has sp³d² hybridisation, octahedral shape and paramagnetic.
(ii) [Co(NH₃)₆]³⁺; Co(27): [Ar] 4s²3d⁷; Co³⁺(27):[Ar]4s⁰ 3d⁶
NH₃ is strong field ligand will cause pairing of electrons.
It has d²sp³ hybridisation, octahedral shape and diamagnetic in nature.
(iii) [NiCl₄]^2-; Ni(28) : [Ar] 4S²3d⁸
Ni²⁺: [Ar] 4s⁰3d⁸, Cl^- is weak field ligand, does not cause pairing of electrons.
It has sp³ hybridisation, therefore, has tetrahedral structure. It is paramagnetic.

(a) The penta-acetate of glucose does not react with hydroxylamine. It indicates that the carbonyl group of glucose is not free as it is present in cyclic form.
(b) Vitamin C is water soluble, that's why it cannot stored in our body.
(c) (i) Peptide linkage Proteins are connected to each other by –CO–NH– bond which is called the peptide linkage.
(ii) Denaturation When a native protein is subjected to physical change or chemical change, the hydrogen bonds are disturbed. As a result, globules unfold and helix gets uncoiled and protein loses its biological activity. This is known as denaturation of proteins.
Or
(c) (i) Anomers In carbohydrates, a pairs of anomers, is a near-identical stereoisomers that differ at only the anomeric carbon.
(ii) Glycosidic linkage The two monosaccharide units are joinied together through an oxide linkage, known as glycosidic linkage.

(i) (a) Metal carbonyls: Metal carbonyls are the compounds in which carbon monoxide (CO) acts as the ligand. The metal-carbon bond in metal carbonyls possesses both \(\sigma\) and \(\pi\) characters, e.g. N(CO)₄[nickeltetracarbonyl]. Its IUPAC name is tetra carbonyl nickel(0).
(b) Chelate: An inorganic metal complex in which there is a close ring of atoms caused by attachment of a ligand to a metal atom at two points. An example is the complex ion formed between ethylene diamine and cupric ion,[Cu(NH₂CH₂CH₂NH₂)₂]²⁺.

(ii) (a) Add BaCl₂ solution. [Co(NH₃)]₅Cl]SO₄ will give white ppt. of BaSO₄.  
 \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right] \mathrm{SO}_{4}+\mathrm{BaCl}_{2}(a q) \)\( \longrightarrow\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right] \mathrm{Cl}_{2}+\mathrm{BaSO}_{4} \downarrow \)
                                                                    \(\text { (White ppt.) }\)
Add AgNO₃(aq) solution [Co(NH₃)₅SO₄] Cl will give white ppt. of AgCl.
\( {\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right] \mathrm{Cl}+\mathrm{AgNO}_{3}(a q)} \) \(\longrightarrow \mathrm{AgCl}+\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right] \mathrm{NO}_{3} \)
                                                                                          \(\text { (White ppt) }\)
(c) Fe³⁺ (4s⁰3d⁵) In strong field \( \Delta_{0}>P t_{2 g}^{5} e g^{0} \)
In weak field \(\Delta_{0}

(i) Ionisation isomerism:
Those isomers which produce different ions in aqueous solution are called ionization isomers. In ionization isomers counter ions are ligands which can replace ligands,
e.g. [Co(NH₃)₅SO₄Br and [Co(NH₃)₅Br]SO₄
(ii) Linkage isomers:
Those isomers which have ambidentate ligands can show linkage isomerism. They differ in donor atom forming coordinate bond,
e.g. [Co(NH₃) ₅ NO₂]²⁺ and [Co(NH₃) ₅ONO]²⁺.
(iii) Coordination isomerism:
It arises from the interchange of ligands between cationic and anionic entities of different metal ions present in a complex,
e.g. [Co(NH₃)₆ ]₆Cr(CN)₆] and [Cr(NH3)₆][Co(CN)₆]
(iv) Solvate isomerism:
They differ in number of solvent molecules forming coordinate bond with central metal ion,
e.g. [Cr(H₂O)₅]CI₃ is violet; whereas [Cr(H₂ O)₅CI]CI₂.H₂ O is greyish green.

cyclic from of glucose (A)

(i)  Carbylamine Reaction: When primary amne reacts with CHCl₃ and KOH, it forms isocyanide which is an offensive smelling compund.
\(RN{ H }_{ 2 }+CHC{ l }_{ 3 }+3KOH\rightarrow RN\overset { = }{ \rightarrow } C+3KCl+3{ H }_{ 2 }O\)

(ii) Diazotisation: When aniline is reacted with NaNO₂ and conc. HCl at 0-5^o C, benzene diazonium chloride is formed.

(iii)  Hoffman's Bromamide Reaction: When amide react with Br₂ and KOH or NaOH to form lower amines, it is called  Hoffman's Bromamide Reaction.

(iv) Coupling reaction: When benzene diazonium chloride reacts with phenol, the orange azo dye is formed.

(v) Ammonolysis: When alkyl halide with an excess of NH₃ primary amines are formed.
C₂H₅Cl+NH₃ \(\rightarrow\)C₂H₅NH₂+HCl
 (vi)Carbylamine reaction (i) Carbylamine reaction When aliphatic/ aromatic primary amines are heated with chloroform and alc KOH, foul-smelling alkyl isocyanides or carbylamines are obtained. Secondary or tertiary amines do not give this test.
(vii) \(\mathbf{P h}-\mathbf{N H}_{2}+\mathbf{C H C l}_{3}+3 \mathbf{K} \mathbf{O H} \stackrel{\Delta}{\longrightarrow} \mathbf{P h}-\mathbf{N C}+3 \mathbf{K} \mathbf{C l}+\mathbf{3 H}_{2} \mathbf{O}\)
2 ° and 3 ° (aromatic/aliphatic) do not give this reaction.

\({ 2 }^{ \circ }\) Amines, i.e., (CH₃)₂NH, on treatment with HNO₂ give oily nitrosamines.

A) Assertion and reason both are correct statements and reason is correct explanation for assertion.
Explanation:
Glucose and fructose differ from each other only at  C1  and  C2   positions.           

(b): In o- or p-aminobenzoic acids, the lone pair of electrons on the -NH₂ group is donated towards the benzene ring. As a result, the basic character of -NH₂ group and acidic character of -COOH group decreases. Therefore, the weakly acidic -COOH group cannot transfer H⁺ ion to the weakly basic -NH₂ group therefore, o and p-aminobenzoic acids do not exist as zwitter ion.

(b): It is because hydrogen bonding is less pronounced in primary and secondary amines than that in alcohols or carboxylic acids and nitrogen is less electronegative than oxygen

(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.

(ii) Glucose on oxidation with HNO₃ gives saccharic acid. This indicates the presence of a one primary alcoholic (-OH) group in glucose.
(iii) The pentaacetate of glucose does not react with hydroxylamine which shows the absence of free aldehydic (-CHO) group.
(iv) In \(\alpha\)-D-glucose, the -OH group at C₁ is towards right, whereas in \(\beta\)-D-glucose, the -OH group at C₁ is towards left. Such a pair of stereoisomers which differ in the configuration only at C₁ are called anomers.

Or
Actually, glucose exists in the cyclic hemiacetal form (hence the aldehyde group is not free) with only a small amount (<0.05%) of the open chain form.
Since, the concentration of the open chain form is low and its reaction with 2,4-DNP is reversible, therefore, formation of 2,4-DNP derivative cannot disturb the equilibrium to regenerate more open chain form from the cyclic hemiacetal form and hence, does not give this test.

(a) When a ligand is bonded through a two different atoms, it is said to be ambidendate ligand,
e.g. \(\mathrm{NO}_2^{-}\), SCN^-, CN^-.
(b) [Co(NH₃)₅Cl]SO₄ and [Co(NH₃)₅SO₄]Cl show ionisation isomerism.
This type of isomerism arises when compounds give different ions in the solution although they have same  composition.
(c) Chelate effect signify the stabilisation of coordination compounds due to the formation of metal chelates. The chelating ligands form more stable complexes than the unidentate analoges because when chelation occurs, entropy decreases and the process becomes more favourable and form a ring complexes which is known as chelate ring.
Or
(c) In complex Na₃[Cr(C₂O₄)₃] the coordination number of Cr is 6 as oxalate is a bidentate ligand.
Let, the oxidation number of Cr be x.
\(\therefore\) 3 + x + 3(-2) = 0
 x = + 3
Thus, oxidation state of Cr be +3.