(iii) 2-Bromo-4-chloropentane

The given quantities are: w₂ = 2 g; K_f = 4.9 K kg mol^–1; w₁ = 25 g,
Observed ΔT_f  = 1·62 K; K_f = 4.9 K kg mol^-1
Substituting these values in equation
\(M_2 ={1000g\ kg^{-1}\times4.9K\ kg\ mol^{-1}\times2.0g\over 1.62K\times25.0g}=242g\ mol^{-1}\)
Thus, experimental molar mass of benzoic acid in benzene is
= 241.98 g mol^–1
Now consider the following equilibrium for the acid:
\(2 \mathrm{C}_6 \mathrm{H}_5 \mathrm{COOH} \rightleftharpoons\left(\mathrm{C}_6 \mathrm{H}_5 \mathrm{COOH}\right)_2\)
If x represents the degree of association of the solute then we would have (1 – x ) mol of benzoic acid left in unassociated form and correspondingly \(\frac{x}{2}\) as associated moles of benzoic acid at equilibrium.
\(1-x+\frac{x}{2}=1-\frac{x}{2}\)
Thus, total number of moles of particles at equilibrium equals van’t Hoff factor i.
But i = \(\frac{\text { Normal molar mass }}{\text { Abnormal molar mass }}\)
\( =\frac{122 \mathrm{~g} \mathrm{~mol}^{-1}}{241.98 \mathrm{~g} \mathrm{~mol}^{-1}} \\ \text {or } \quad \frac{x}{2} =1-\frac{122}{241.98}=1-0.504=0.496 \\ \text {or } \quad x =2 \times 0.496=0.992 \)
Therefore, degree of association of benzoic acid in benzene is 99.2 %.

A nucleoside contains only two basic components of nucleic acids namely a pentose sugar and a nitrogenous base.
A nucleotide contains all the three basic components of nucleic acids namely a phosphoric acid group, a pentose sugar and a nitrogenous base.

 \((i)\ { { C }H }_{ 3 }CH=CH-\overset { { 1 }^{ \circ } }{ { C } } { H }_{ 2 }Br\ \ (ii){ { C }H }_{ 3 }-\overset { { 2 }^{ \circ } }{ { C } } { H }Br-CH=CH-{ { C }H }_{ 3 }\ \ (iii){ { C }H }_{ 3 }\overset { { 3 }^{ \circ } }{ - } \overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CI } } }{ C } } -Br\ \) 
            1-Bromobut-2-enc                                   4-Bromopent-2-ene                                    2-Bromo-2-methylpropane
             (1^o Alkyl halide)                                          (2^o Alkyl halide)                                             (3^o Alkyl halide)    

In [NiCl₄]^2-, Ni is +2 oxidation state with the configuration 3d⁸4s⁰. Cl^- is weak ligand. It cannot pair up the electrons in 3d orbitals. Hence, it is paramagnetic. In [Ni(CO)₄], Ni is in zero oxidation state with the configuration 3d⁸4s². In the presence of CO ligand, the 4s electrons shift to 3d to pair up 3d electrons. Thus, there is no unpaired electron present. Hence, it is diamagnetic.

(i)The ion whose one end is positively charged and other end is negatively charged is called Zwitter ion, e.g., 
\({ H }_{ 2 }N-CH_{ 2 }-COOH\rightleftharpoons { H }_{ 3 }^{ \oplus }N-CH_{ 2 }-COO^{ - }\)
(ii) Glycosidic Linkage: The oxide linkage between monosachharide units in oligo and polysachharide is called glycosidic linkage, e.g.

S_N1 Reactions: They are substitution nucleophilic unimolecular reactions in which the rate of the reaction depends on the concentration of only one reactant. Product formation takes place by the formation of carbo cation as reaction intermediate. For example:

S_N2 reactions they are substitution nucleophilic bimolecular reactions in which rate of the reaction depends on the concentration of two reactants. For example:
​​​​​
The product formation takes place by formation of transition state.

\(NaCI\longrightarrow { Na }^{ + }+{ CI }^{ - }\)
\(\therefore i=2,\triangle { T }_{ f }=i\times { K }_{ f }\times \frac { { W }_{ B } }{ { M }_{ B } } \times \frac { 1000 }{ { W }_{ A } } \)
\(\\ \Rightarrow 3=2\times 1.86\times \frac { { W }_{ B } }{ 58.5 } \times \frac { 1000 }{ 1000 }\)
\(\Rightarrow { W }_{ B }=\frac { 3\times 58.5 }{ 2\times 1.86 } =\frac { 175.5 }{ 3.72 } =47.17\ g\)

(a) (i) Azeotrope: Those solutions which distill out unchanged in their composition are called azeotropes. They are constant boiling mixtures.
(ii) Osmotic pressure: It is an extra pressure which must be applied on solution side so as to stop the flow of solvent molecules into solution when both are separated by a semipermeable membrane.
(iii) Colligative property: The property which depends on the number of particles of solute and not on the nature of solute is called colligative property.
(b) Molarity (M)
= \(\frac{W_{B}}{M_{B}} \times \frac{1000}{\text { Volume of solution in } \mathrm{mL}}\) 
= \(\frac{9.8}{98} \times \frac{1000}{\frac{\text { Mass of solution }}{\text { density of solution }}}\) 
= \(\frac{9.8}{98} \times \frac{1000}{\frac{100}{1.02}}=1.02 \mathrm{~mol} \mathrm{~L}^{-1}\) 

\((i)\quad { CH }_{ 3 }-\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CH }_{ 3 } } }{ C } } -{ CH }_{ 3 }\) 
 All the H atoms are equivalent.
\((ii)\quad \overset { a }{ { CH }_{ 3 } } -\overset { b }{ { CH }_{ 2 } } -\overset { c }{ \underset { n-Pentane }{ { CH }_{ 2 } } } -\overset { b }{ { CH }_{ 2 } } -\overset { a }{ { CH }_{ 3 } } \)   
Replacement of a, b atom gives different products.
\((iii)\quad \overset { a }{ { CH }_{ 3 } } -\underset { \overset { | }{ { CH }_{ 3 } } }{ \overset { b }{ { CH }_{ 2 } } } -\overset { c }{ { CH }_{ 2 } } -\overset { d }{ { CH }_{ 3 } } \) 
Replacement of a, b, c and d H atoms give different products.

There are coordinate bonds in the following complexes.
(a) [Fe(CN)₆]^4-
Fe(26) has electronic configuration [Ar] 4s²3d⁶.
Fe²⁺ has electronic configuration 4s⁰3d⁶
CN^- ion causes pairing of electrons because it is a strong field ligand.
It has octahedral shape and is diamagnetic in nature due to the absence of unpaired electrons.
(b) [FeF₆]^3- 
F^- is weak field ligand, does not cause pairing of electrons.
(c) [Co(C₂O₄)₃]^3-
(d)  [CoF₆]^3-
F^- is weak field ligand, cannot cause pairing of electrons.

(i) [Co(C₂O₄)₃]^3- is more stable.
(ii)  [CoF₆]^3- is outer orbital complex.
(iii) [Co(C₂O₄)₃]^3-  is low spin complex.

tert-Butyl bromide readily loses Be ion to form stable tert-butyl carbocation. Therefore, it undergoes reaction by SNI mechanism which occurs in two steps. In the first step, tert-butyl carbocation is formed. This step is slow and hence is the rate determining step of the reaction. In the second step, the tert-butyl carbocation is readily attacked by OH- ion to form tert-butyl alcohol.

On the other hand, n-butyl bromide does not undergo ionization to produce n-butyl carbocation because it is not stable. Therefore, it prefers to undergo reaction by SN₂ mechanism which occurs in one step through a transition state involving nucleophilic attack of the OH- ion. from the back side with simultaneous expulsion of Br^- ion from the front side.

Molar mass of C₂H4O₂: 12 × 2 + 1 × 4 + 16 × 2 = 60 g mol^-1
\(\text {Moles of } \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}=\frac{2.5 \mathrm{~g}}{60 \mathrm{~g} \mathrm{~mol}^{-1}}=0.0417 \mathrm{~mol}\)
\(\text {Mass of benzene in } \mathrm{kg}=75 \mathrm{~g} / 1000 \mathrm{~g} \mathrm{~kg}^{-1}=75 \times 10^{-3} \mathrm{~kg}\)
\(\text {Molality of } \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}=\frac{\text { Moles of } \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}}{\text { kg of benzene }}=\frac{0.0417 \mathrm{~mol} \times 1000 \mathrm{~g} \mathrm{~kg}^{-1}}{75 \mathrm{~g}}\)
= 0.556 mol kg^-1

There are 3 main types of RNA
1. mRNA - Messenger RNA
2. tRNA - Transfer RNA
3. rRNA - Ribosomal RNA

Ambident Nucleophile- An anionic nucleophile, which has two nucleophilic centers, or two negative sites is known as an ambident nucleophile. This negative charge is delocalized due to resonance.
Example – Cyanide and Thiocyanate are examples of ambident nucleophiles. 
^-C≡N   ↔   :C=N^-
S=C=N^- ↔  ^-S - C≡ N

\(\frac { { p }^{ o }-{ p }_{ s } }{ { p }^{ o } } ={ x }_{ 2 }\) (mole fraction of solute in solution) - Raoult's law.

In a ideal solution, solute does not undergo dissociation or association. Hence, van't Hoff factor = 1.

(i) (b): When compound (A) reacted with Na-metal, it gave a compound D(C₈H₁₈) which is different from the compound obtained when n-butyl bromide reacted with Na metal and hence the
compound (A) must be isobutyl bromide.
\(2 \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br}+2 \mathrm{Na}\) \(\overset{Wurtz reaction}\rightarrow\)  \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\)

(i) (c): Ligands are named in alphabetical order irrespective of their charge.
(ii) (b)
(iii) (d)
(iv) (d)