(i) These are phenol and formaldehyde.
(ii) It is a condensation reaction.
(iii) Soft bakelites are used for making glues for binding laminated sheets, wooden planks and in lacquers. Hard bakelites are used in the manufacture of combs, fountain pens, electric goods etc.

(i) Iron is present in + 3 oxidation state as Fe (III).
(ii) Iron hydroxide i.e., Fe(OH)₃ is insoluble in water and is therefore, not assimilated in the soil.
(iii) Fe(III)-EDTA complex is readily absorbed by the soil as it is water soluble.
(iv) The addition of this complex compound in proper amount makes plants healthy and the yield of fruits gets increased. But its deficiency also affect adversely so we will provide Fe-EDTA complex.

(a) (i) Molarity: Molarity of a substance in a solution is equal to the number of moles of the substance present in one litre of the solution.
i.e., Molarity = \(\frac { No.\ of\ moles\ of\ substance }{ Volume\ of\ solution\ in\ L } \)
(ii) Molal elevation constant (K_b): It is also called ebullioscopic constant. It is equal to the change in boiling point of one molar solution.
\(\Delta\)T_b = K_b . m
So, when, Molarity = 1,\(\Delta\) T_b = K_b
(b)Given; Mass of urea, W_B = 15 g
Molar mass of rea, M_B = 60 g
The solution of urea in water is isotonic to that of glucose solution.
So,  \(\pi _{ urea }=\pi _{ Glucose }\)
\(C_{ urea }RT=C_{ Glucose }RT\)
\(\frac { { n }_{ urea } }{ V } RT=\frac { { n }_{ Glucose } }{ V } RT\)
\(=\frac { 15 }{ 60 } =\frac { { W }_{ Glucose }V }{ 180 } \)
\(={ W }_{ Glucose }=\frac { 18\times 18 }{ 60 } \)
= 45 g
So, 45 g of glucose is present in 1 L of solution.

(i) The industries involving the roasting of sulphur ores must be installed at place far from the cities so that the pollution caused by release of S0₂ gas may not affect human beings.
(ii) Sulphuric acid is one of the most useful industrial chemicals. It is used in strongest batteries, in textiles paper and leather industry, in manufacture of points and pigments.

(a) (i) In gaseous state, hydrogen halides are covalent. But in aqueous solution, they ionise and behave as acids. The acidic strength of these acids decreases in the order:
HI > HBr > HCI > HF
Thus, HF is the weakest acid and HI is the strongest acid among these hydrogen halides. The above order of acidic strength is reverse of that expected on the basis of electronegativity. Fluorine is the most electronegative halogen, therefore, the electronegativity difference will be maximum in HF and should decrease gradually as we move towards iodine through chlorine and bromine. Thus, HF should be most ionic in nature and consequently, it should be strongest acid. Although many factors contribute towards the relative acidic strengths, the major factor is the bond dissociation energy. The bond dissociation energy decreases from HF to HI so that HF has maximum bond dissociation energy and HI has the lowest value.
Since H-I bond is weakest, it can be dissociated into H+ and 1- ions readily while HF can be dissociated with maximum difficulty. Thus, HI is the strongest acid while HF is the weakest acid among the hydrogen halides.
(ii) Oxygen molecule is held by weak van der Waals forces because of the small size and high electronegativity of oxygen. On the other hand, sulphur molecules do not exist as \({ S }_{ 2 }\)   but from polyatomic molecules having eight atoms per molecule \({ S }_{ 8 }\)  linked by single bonds. Therefore, S atoms are strongly held together by intermolecular forces and its melting point is higher than that of oxygen. Hence, there is large difference in melting and boiling points of oxygen and sulphur.
(iii) In molecular nitrogen, there is a triple bond between two nitrogen atoms (N-N) and it is nonpolar in character. Due to the presence of a triple bond, it has very high bond dissociation enthalpy (\(941.4kJ{ mol }^{ -1 }\)) and therefore, it does not react with other elements under normal conditions and is very unreactive. However, it may react at higher temperatures.

Carbohydrates which differ in configuration at the glycosidic carbon (i.e. \({ C }_{ 1 }\) in aldoses and \({ C }_{ 2 }\) in ketoses) are called anomers while those which differ in configuration at any carbon other than glycosidic carbon are called epimers. For example, \(\alpha \)-D-glucose and \(\beta \)-D-glucose are anomers since they differ in configuration at \({ C }_{ 1 }\) (glycosidic carbon) while glucose and mannose are called epimers since they differ in configuration at \({ C }_{ 2 }\)(other than the glycosidic carbon \({ C }_{ 1 }\) ). In other words, glucose and mannose are Cr epimers. Similarly, we can show that glucose and galactose are \({ C }_{ 4 }\) -epimers since they differ in configuration only at \({ C }_{ 4 }\).

The allyl carbocation is resonance stabilized and hence is as stable as a 30 carbocation
Therefore, on treatment with Lucas reagent, allyl alcohol gives white turbidity in less than 1 min.l-Propanol, on the other hand, does not react with Lucas reagent.

(i) Loss of a proton from an oxime gives a conjugate base which is stabilized by resonance but the conjugate base of NH₂OH is not.
(ii) To prepare iodoform from acetone, I⁺ is required which is supplied by IO^- ion but not by I^- ion as shown below:
(iii) During oxidation of toluene with CrO/H₂SO₄, the intermediate benzaldehyde formed readily undergoes oxidation to form benzoic acid due to the presence of H₂O in H₂SO₄,
\(\underset{Toluene}{C_6H_5-CH_3}\xrightarrow[\Delta]{CrO_3/H_2SO_4}\underset{Benzaldehyde}{C_6H_5-CHO}\xrightarrow{H_2O}\underset{Benzaldehyde\ hydrate}{C_6H_5CH(OH)_2}\xrightarrow{CrO_3/H_2SO_4}\underset{Benzalde\ acid}{C_6H_5COOH}\)
However, with CrO ₃3 in (CH₃CO)₂O, due to the absence of H₂O as soon as benzaldehyde is formed, it reacts with acetic anhydride to form benzylidene diacetate which does not undergo further oxidation. In this way, oxidation of benzaldehyde to benzoic acid is prevented. The gem-diacetate thus formed upon subsequent hydrolysis with alkali or acid gives benzaldehyde
\(\underset{Toluene}{C_6H_5CH_3}\xrightarrow[273-283K]{CrO_3/H_2SO_4}\underset{Benzylidene diacetate\\ (gem-diacelate)}{C_6H_5CH(OOH_3)_2}\xrightarrow[(Hydrolysis)]{H_3O^+}\underset{Benzaldehyde}{C_6H_5CHO}+\underset{Acetic\ acid}{2CH_3COOH}\)

tert-Alkyl halides prefer to undergo dehydrohalogenation in presence of a strong base such as Na metal instead of undergoing Wurtz reaction as explained below:
\(\underset{tert-Butyl\ bromide}{(CH_3)_3C-Br}+2Na\longrightarrow\underset{tert-Butylsodium}{(CH_3)_3Na^+}+Na^+Br^-\)
Thus, only rand 2° alkyl halides undergo Wurtz reaction while 3° alkyl halides prefer to undergo dehydrohalogenation to form alkenes.

(a) Hexaamminecobalt (III) chloride
(b) Tetraamminechloridonitrito-N-cobalt(III) chloride
(c) Hexaamminenickel (II) chloride.
(d) Diamminechloridomethylamineplatinum (II) chloride
(e) Hexaaquamanganese (II) ion
(f) Tris ethane (1, 2-diamine) cobalt (III) ION.
(g) Hexaaquatitanium (III) ion
(h) Tetrachloridonickelate (II) ion
(f) Tetracarbonylnickel (0)

(i) Molar mass of CH₂Cl₂ = 12 × 1 + 1 × 2 + 35.5 × 2 = 85 g mol^–1
Molar mass of CHCl₃ = 12 × 1 + 1 × 1 + 35.5 × 3 = 119.5 g mol^–1
\(\text {Moles of } \mathrm{CH}_{2} \mathrm{Cl}_{2} \quad=\frac{40 \mathrm{~g}}{85 \mathrm{~g} \mathrm{~mol}^{-1}}=0.47 \mathrm{~mol}\)
\(\text {Moles of } \mathrm{CHCl}_{3} \quad=\frac{25.5 \mathrm{~g}}{119.5 \mathrm{~g} \mathrm{~mol}^{-1}}=0.213 \mathrm{~mol}\)
\(x_{\mathrm{CH}_{2} \mathrm{Cl}_{2}}=\frac{0.47 \mathrm{~mol}}{0.683 \mathrm{~mol}}=0.688\)
x_CHCl3 = 1.00 – 0.688 = 0.312
\(p_{\text {total }}=p_{1}^{0}+\left(p_{2}^{0}-p_{1}^{0}\right) x_{2}=200+(415-200) \times 0.688\)
= 200 + 147.9 = 347.9 mm Hg
(ii) y₁ = p₁/p_total, we can calculate the mole fraction of the components in gas phase (y₁).
\(p_{\mathrm{CH}_{2} \mathrm{Cl}_{2}}=0.688 \times 415 \mathrm{~mm} \mathrm{Hg}=285.5 \mathrm{~mm} \mathrm{Hg}\)
\(p_{\mathrm{CHCl}_{3}}=0.312 \times 200 \mathrm{~mm} \mathrm{Hg}=62.4 \mathrm{~mm} \mathrm{Hg}\)
\(y_{\mathrm{CH}_{2} \mathrm{Cl}_{2}}=285.5 \mathrm{~mm} \mathrm{Hg} / 347.9 \mathrm{~mm} \mathrm{Hg}=0.82\)
\(y_{\mathrm{CHCl}_{3}}=62.4 \mathrm{~mm} \mathrm{Hg} / 347.9 \mathrm{~mm} \mathrm{Hg}=0.18\)

(i) Cast iron is made by melting pig iron with scrap iron and coke using hot air blast. It has slightly lower carbon content (in pig iron, C is 4%) and in cast iron, C is about 3% and is extremely hard and brittle.
(ii) Leaching of alumina from bauxite ore Bauxite usually contains SiO₂, iron oxide and titanium oxide (TiO₂) as impurities.
Powdered ore is digested with cone. NaOH solution at 473-523 K and 35-36 bar pressure.Al₂O₃ and SiO₂ are dissolved in the solution while impurities do not.
\(Al_2O_3(S) +2NaOH(aq) + 3H_2O(l) \xrightarrow[35-36\ bar]{473-523K}\underset{Sodium\ aluminate}{2Na[Al(OH)_4](aq)}\)
Filtrate is neutralised by passing CO2 gas and hydrated Alp j is precipitated. Some freshly prepared hydrated Al₂O₃ is also added to solution to induce precipitation.
\(2Na [Al(OH)_4] (aq)+ 2CO_2(9)⟶\underset{(ppt.)}{Al_2O_3.xH_2O(s)}+2NaHCO_3(aq)\)
Precipitate is filtered, washed, dried and heated to give back pure Al₂O₃.
\(Al_2O_3. xH_2O( s)\xrightarrow{1470K}\underset{Alumina}{Al_2O_3(s)}+xH_2O(g)\)

Aniline forms the salt anilinium chloride with HCIwhich is water soluble
 

Metallic solids.

Vitamins: Vitamins are group of organic compounds which are required in very small amounts for the healthy growth and functioning of animal organism. They cannot be made by organism and so have to be part of our diet. The deficiency of a vitamin can cause a specific disease, e.g.
(i) Vitamin B, deficiency causes pernicous anaemia.
(ii) Vitamin B, deficiency causes convulsion. 

(a) All the six ligands are assumed to be positioned symmetrically along the axis with the metal atom at the origin.

(b) As the ligand approaches, there is an increase in energies of all d-orbitals relative to that of free ion in spherical field. The orbitals \({ d }_{ { x }^{ 2 }-{ y }^{ 2 } }\)  and \({ d }_{ { z }^{ 2 } }\) . lie on axis, therefore, their energy is raised. It is called e I the other orbitals d_xy  d _yz d have lower _zx have lower energy because they lie in between the axis are less repelled. These orbitals are t_2g .
(c) The difference in energy of these two set of orbitals is called energy of separation \({ (\Delta }_{ 0 })\)
(ii) Depending upon the ability of the ligands to cause splitting, i.e., strength of ligands are arranged in increasing order, the series so produced is called Spectrochemical series.
 \(({ I }^{ - }<{ Br }^{ - }<{ Cl }^{ - }<{ F }^{ - }<\underset { \overset { | }{ { COO }^{ - } } }{ { COO }^{ - } } <{ H }_{ 2 }O)\)

(i) 8MnO₄^-(aq)+3S₂O₃^2-(aq)+H₂O(l) \(\rightarrow \)8MnO₂+6SO₄^2-+2OH^-
(ii) Cr₂O₇^2-(aq) + 6Fe²⁺(aq) +14H⁺(aq) \(\rightarrow \) 2Cr³⁺+6Fe³⁺+7H₂O

(i) Certain amount of activation energy is essential even for such reactions to be
thermodynamically feasible, therefore, heating is required.
(ii) Leaching of alumina from bauxite ore
Al₂O₃ (s)+ 2NaOH (aq) + 3H₂O(l)\(\xrightarrow[35-36bar]{473-523K}\)2Na [Al (OH)4](aq)
2Na [Al (OH)₄] (aq) + CO₂(g) ⟶ Al₂O₃.xH₂O(s) + 2NaHCO₃
Al₂O₃.xH₂P(s) \(\xrightarrow{1470K}\)\(\underset{Pure\ alumina}{Al_2O_3(s)}\)+xH₂O(g)
Electrolytic reduction of alumina
2Al₂O₃ + 3C ⟶  4Al + 3CO₂
The electrolytic reactions are
At cathode Al³⁺(melt) + 3e^- ⟶  Al(I)
Atanode C (s)+ O^2-(melt) ⟶ CO (g)+ 2e^-
C(s)+ 2O^-(melt) ⟶ CO² (g)+ 4^e-

(i) \({ C }_{ 6 }{ H }_{ 5 }{ NO }_{ 2 }\overset { Sn/HCI }{ \longrightarrow } { { C }_{ 6 }{ H }_{ 5 }{ NH }_{ 2 }\overset { NaNO_{ 2 }+HCI }{ \underset { 273K }{ \longrightarrow } } }{ C }_{ 6 }{ H }_{ 5 }{ N }_{ 2 }^{ + }{ CI }^{ - }\overset { { H }_{ 2 }O }{ \longrightarrow } { C }_{ 6 }{ H }_{ 5 }OH+{ N }_{ 2 }+HCI\)
(ii)\({ C }{ H }_{ 3 }CN\overset { { H }_{ 2 }O/{ H }^{ + } }{ \longrightarrow } { C }{ H }_{ 3 }-\overset { \begin{matrix} O \\ \parallel \end{matrix} }{ C } -OH\overset { NH_{ 3 } }{ \underset { \triangle }{ \longrightarrow } } { CH }_{ 3 }{ CONH }_{ 2 }\overset { { Br }_{ 2 }+KOH }{ \longrightarrow } { CH }_{ 3 }{ NH }_{ 2 }\)

Lightning taking place from time to time helps in converting atmospheric nitrogen and oxygen into nitric acid as a result of series of reactions.
\(N_{ 2(g) }+O_{ 2(g) }\overset { Lightenig }{ \longrightarrow } 2NO_{ (g) }\\ 2NO_{ (g) }+O_{ 2 }\longrightarrow 2NO_{ 2(g) }\\ 4NO_{ 2(g) }+O_{ 2(g) }+2H_{ 2 }O_{ (l) }\longrightarrow 4HNO_{ 3(aq) }\)
Nitric acid dissolves in rain water and is converted into calcium nitrate by reacting with calcium salts present in the soil. Calcium nitrate and other nitrates are the nutrients for the soil which gives better yield of crop.

This is because of ability to form multiple bonds.

A colloidal state has larger surface area of sol particles and therefore, are more effectively adsorbed.Therefore the medicines in colloidal state are more easily assimilated or adsorbed and are more effective.

(i) 0.01488 min^-1
(ii) 154.77 min
(iii) 15 minutes.

(a) 0.001244 ohm^-1 cm^-1  (b) 165.87 ohm^-1 cm² mol^-1

Artificial sweeteners: The artificial sweeteners are another type of food additives, e.g. Ortho-sulphobenzimide (saccharin) is marketed as soluble sodium or calcium salt. It is 550 times sweeter than cane sugar. It is lifesaver for diabetic patients and is of great value to people who need to control intake of calories. Aspartame is unstable at cooking temperature, therefore, it can be used as a sugar substitute to cold foods and soft drinks. Alitame is more stable than aspartame during cooking. It can be used to prepare sweets for diabetic patients. Sucralose (trichloro derivative of sucrose) is predicted to become a great commercial success. It is stable at cooking temperature. It does not provide calories.

Amines are stronger bases than amines followed by amines. Further, among amines, (C₂H₅)₂NH is more basic than (CH₃)₂NH due to stronger +I-effect of the CH₃CH₂ over CH₃ group. Thus, option (b) is correct.