(i) Brominatin of alkene to give bromo alkane.

(iii) In this reaction, benzoyl peroxide acts as a radical initiator. The mechanism involves free radicals.
\({ H }_{ 2 }C=CH+H-Br\overset { \overset { Benzoyl }{ Peroxide } }{ \longrightarrow } C{ H }_{ 3 }-C{ H }_{ 2 }-Br\)

Compressibility factor is the ratio of PV to nRT.
Z = \(\frac{PV}{nRT}\)
For ideal gases PV = nRT i.e., Z = 1
At high pressures Z > 1 (Positive deviation)
At inter mediate pressures Z < 1 (negative deviation)

T_b = 351 K
ΔH_vap = 39840 Jmol^-1
ΔS_V = ?
ΔS_v = \(\frac { { \triangle H }_{ vap } }{ { T }_{ b } } \)
ΔS_v = \(\frac { 39840 }{ 351 } \)
ΔS_v = 113.5 JK^-1 mol^-1

Statues turn black due to the formation of lead sulphide. Hydrogen peroxide oxidises black coloured lead sulphide to white coloured lead sulphate, thereby restoring the colour.
PbS + 4H₂O₂ ➝ PbSO₄ + 4H₂O

(i) Nitrous acid: HNO₂
+ 1 + x - 2 x 2 = 0
x = +3
(ii) Nitric acid: HNO3
+ 1 + x - 2 x 3 =0
x = +5.

Given K_eq= 10
Gas constant R = 8.314 JK^-1 mol^-1
T=300K
The relationship between Free energy change ΔG and equilibrium constant K is ΔG^o=-RTlnK
Since K, T and R are positive values, ΔG^o will be negative.
When ΔG is -ve, the process is spontaneous and feasible

Calcium Sulphate (plaster of paris), CaSO₄. 1/2H₂O :
It is a hemihydrate of calcium sulphate. It is obtained when gypsum, CaSO₄ .2H₂O,is heated to 393 K
2(CaSO₄.2H₂O) ⟶ 2CaSO₄,H₂O + 3H₂O
Above 393 K, no water of crystallisation is left and anhydrous calcium sulphate, CaSO₄ is formed. This is a known 'dead burnt plaster'.
It has a remarkable property of setting with water. on mixing with an adequate quantity of water it forms a plastic mass that gets into hard solid in 5 to 15 minutes.

Z = 118; [₈₆Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶
In the periodic table the element with Z = 118 is located in p-block,
Period no = 7 (as n = 7 for valence shell)
Group no. = 18 (group no = 10+ ns electrons + np electrons) (n - outer most shell)

(i) Ethanol: Formaldehyde reacts with CH₃MgI to give an addition product which onhydrolysis yields ethanol 

(ii) 2-Propanol : Acetaldehyde react with CH₃MgI to give an addition product which on hydrolysis yields 2-propanol.

(i) When half filled orbitals of two atoms overlap, a covalent bond will be formed between them.
(ii) The resultant overlapping orbitals are occupied by the two electrons with opposite spins. For example when H2 is formed, the two Is electron of two hydrogen atoms get paired up and occupy the overlapped orbitals.
(iii) The strength of a covalent bond depends upon the extent of overlap of atomic orbitals. Greater the overlap, larger is the energy released and stronger will be the bond formed.
(iv) Each atomic orbital has a specific direction (except s-orbital which is spherical) and hence orbital overlap takes place in the direction that maximises overlap.
(v) Depending upon the nature of overlap, the bonds are classified as c covalent bond and n covalent bond.
(vi) When two atomic orbitals overlap linearly along the axis, the resultant bond is called a sigma (c) bond. This overlap is also called "head-on-overlap" or "axial overlap".
(vii) When two atomic orbitals overlap sideways the resultant covalent bond is called a pi (n) bond.

(i) BOD and COD

(ii) Viable and non-viable particulate pollutants

W = 0.3 g
x = 0.54 g
y = 0.88 g
\( \% \mathrm{C} =\frac{12}{44} \times \frac{\mathrm{y}}{\mathrm{w}} \times 100=\frac{12}{44} \times \frac{0.88}{0.30} \times 100=80 \% \)
\(\% \mathrm{H}=\quad \frac{2}{18} \times \frac{\mathrm{x}}{\mathrm{w}} \times 100=\frac{2}{18} \times \frac{0.54}{0.30} \times 100=20 \%\)

\(K_c={[NH_3]^4[O_2]^5\over [NO]^4[H_2O]^6}\)
\(4 \mathrm{NO}_{(\mathrm{g})}+6 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})} \rightleftharpoons 4 \mathrm{NH}_{3(\mathrm{~g})}+5 \mathrm{O}_{2(\mathrm{~g})}\)

 (a) Alkali metals have low ionization enthalpies.
They have a strong tendency to lose 1 electron to form unipositive ions. Thus they show an oxidation state of + 1 and are strongly electropositive.
(b) Valence electrons of alkali metals like Na and K easily absorb energy from the flame and are excited to higher energy levels. When these electrons return to the ground state, the energy is emitted in the form of light. Magnesium atom has small size so electrons are strongly bound to the nucleus. Thus they need large amount of energy for excitation of electrons to higher energy levels, which is not possible in Bunsen flame.
(c) Due to the small size of Li⁺ it has a strong positive field, which attracts the negative charge so strongly that it does not permit the oxide ion (O^2-) to combine with another oxygen atom to form peroxide ion.
(d) Among alkali metals, lithium has the most negative electrode potential (Ee = -3.04 V), so it is the strongest reducing agent in the aqueous solution.

\(\therefore\) The empirical formula is C₁₄H₉Cl₅.
Calculation of Molecular formula:
The empirical formula mass(C₁₄H₉Cl₅) = \((14\times 12)+(9\times1)+(5\times 35.5)\)
= 168 + 9 + 177.5 = 354.5
\(n=\frac{Molecular\ mass}{Empirical\ formula\ mass}=\frac{354.5}{354.5}=1\)
Molecular formula = (Empirical formula)_n
= (C₁₄H₉Cl₅)_l
\(\therefore\) Molecular formula = C₁₄H₉Cl₅

(a) The number of subshells is the same as the number used to designate the shell ie., n = 4 so contains 4 sub shells.
(b) The subshells in the fourth shell are designated as 4s. 4p. 4d and 4f
(c) The number of orbitals in s, p, d and subshell is 1,3,5 and 7-respectively.
(d) Each orbital can contain a maximum of two electrons.
4s - 1 orbital - 2 electrons
4p - 3 orbital - 6 electrons
4d - 5 orbital -10 electrons
4s - 7 orbital - 14 electrons

The group metal - 1 which is present in common salt is sodium.
So (A) is sodium
Sodium reacts with hydrogen (B) to give, sodium hydride (C). In sodium hydride the hydrogen is present in -1 oxidation state.
\(2\underset { (A) }{ Na } +\underset { (B) }{ { H }_{ 2 } } \rightarrow 2\underset { (C) }{ NaH } \)
So (B) hydrogen and (C) is sodium hydride
H₂ reacts with oxygen gas (D) to give an universal solvent, water (E) follows:
\(2\underset { (B) }{ { H }_{ 2 } } +{ O }_{ 2 }\rightarrow 2\underset { (D) }{ { H }_{ 2 }O } \)
So (E) is water. Water is the universal solvent
Water (E)  reacts with sodium  (A) follow to give (F), which is a strong base.
\(2\underset { (E) }{ { H }_{ 2 }O } +\underset { (A) }{ 2Na } \rightarrow 2\underset { (F) }{ NaOH } +{ { H }_{ 2 } } \)
So (F) is sodium hydroxide.

Statement : "No two electrons in an atom can have the same set of values of all four quantum numbers"
Explanation : It means that, each electron must have unique values for the four quantum numbers (n, l, m and s).
For the lone electron present in hydrogen atom, the four quantum numbers are: n = 1; l = 0; m = 0 and s = +1/2. For the two electrons present in helium, one electron has the quantum numbers same as the electron of hydrogen atom, n = 1.
l = 0, m = 0 and s = +1/2. For other electron, the fourth quantum number is different i.e., n = 1, l = 0, m = 0 and s = -1/2.
As we know that the spin quantum number can have only two values +1/2 and - 1/2, only two electrons can be accommodated in a given orbital in accordance with pauli exclusion principle.

1. Electronic configuration of hydrogen atom is Is 1.
2. During the formation of H₂ molecule, the Is orbitals of two hydrogen atoms containing one unpaired electron with opposite spin overlaps with each other along the internuclear axis. This overlap is called s-s overlap. Such axial overlap results in the formation of a sigma (0-) covalent bond.

i) DDT: DDT can be prepared by heating a mixture of chlorobenzene with chloral (Trichloro acetaldehyde) in the presence of con. H₂SO₄,

ii) Chloroform :The reaction of methane with excess of chlorine in the presence of sunlight will give carbon tetrachloride as the major product.
\(\underset { Methane }{ { CH }_{ 4 }+4C{ l }_{ 2 }\overset { h\gamma }{ \longrightarrow } } +\underset { Carbon \ tetrachloride }{ 4HCl } \)
iii) Bipheenyl :
\(\underset { Chlorobenzene }{ { C }_{ 6 }{ H }_{ 5 }Cl } +2Na+Cl-{ C }_{ 6 }{ H }_{ 5 }\overset { Ether }{ \longrightarrow } \underset { Biphenyl }{ { C }_{ 6 }{ H }_{ 5 }-{ C }_{ 6 }{ H }_{ 5 }+2NaCl } \)
iv) Chloropicrin : Chloroform reacts with nitric acid to form chloropicrin.(Trichloro nitro methane)
\(\underset { Chloroform }{ { CH }_{ 3 }+HN{ O }_{ 3 }\overset { \triangle }{ \longrightarrow } } \underset { Chloropicrin }{ C{ Cl }_{ 3 }N{ O }_{ 2 }+{ H }_{ 2 }O } \)
v) Freon-12 :Freon - 12 is prepared by the action of hydrogen fluoride on carbon tetrachloride in . the presence of catalylic amount of antimony pentachloride. is is called swartz reaction
\(\underset { Carbontetrachloridew }{ { CCl }_{ 3 }+2HF\overset { SbC{ l }_{ 5 } }{ \longrightarrow } } \underset { Freon-12 }{ 2HC{ l }+CCl_{ 2 }F_{ 2 } } \)

No.of moles ; n = \(\frac{\mathrm{m}}{\mathrm{M}}=\frac{5.6}{56}=0.1 \mathrm{~mol}\)
(i) V = 500 ml = \(\frac{500}{1000}=0.5 \mathrm{~L} \)
Molarity = \(\frac{\mathrm{n}}{\mathrm{v}}=\frac{0.1}{0.5}=0.2 \mathrm{M} \)
(ii) V = IL 
Molarity = \(\frac{\mathrm{n}}{\mathrm{v}}=\frac{0.1}{1}=0.1 \mathrm{M} \)

No.of moles = \(\frac { mass\ of\ the\ substance }{ Molar\ mass\ of\ the\ substanc } =\frac { W }{ M } \)
Molar mass of ethane (C₂H₆) = 24 + 6 = 30
\(\therefore\) Number of moles in 60 g of ethane = \(\frac { 60 }{ 30 } \) = 2 moles.

For the reaction to be spontaneous
ΔG = Negative (ΔG < 0)
i.e., ΔH - TΔS < 0
or T > \(\frac { ΔH }{ ΔS } \)
i.e., T > \(\frac { 400ｘ1000 }{ 2000 } \)
= T >200 K
The reaction will be spontaneous above 200 K

Absolute zero is a temperature at which all gases have zero volume. This temperature cannot be obtained. It has a value of - 273 .15°C and theoretically it is the lowest temperature obtainable.

The solubility product of NaCl is lower than that of NaOH. The more soluble a substance is, the higher the K_sp value it has In aqueous solution NaOH gives OH^- ions. It can be solvated by establishing H-bonds with water molecules. So it is more water soluble.

a) Principal quantum number defines energy and size of an orbital.
b) Azimuthal quantum number defines shape of an orbital
c) Magnetic quantum number defines spatial orientation (direction) of an orbital.

i) Both (A) and R are correct and (R) is the correct explanation of (A)

both assertion and reason are true and reason is the correct explanation of assertion