(i) Since, the byproduct of roasting of sulphide ore is SO₂' It also turns lime water milky. Therefore, gas 'B ' must be SO_2.
(ii) As the gas B is obtained when amorphous solid 'A' burns in air therefore, amorphous solid 'A' must be sulphur, S₈
\(\begin{aligned} &\mathrm{S}_{8}+8 \mathrm{O}_{2} \stackrel{\Delta}{\longrightarrow} 8 \mathrm{SO}_{2}\\ &\text { (A) }\\ &2 \mathrm{ZnS}(s)+3 \mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{ZnO}(s)+2 \mathrm{SO}_{2} \end{aligned}\)
(iii) Gas B reduces acidified aqueous KMnO₄ solution and reduces Fe³⁺ to Fe²⁺ salts as shown below:
\(2 \mathrm{MnO}_{4}^{-}+5 \mathrm{SO}_{2}+2 \mathrm{H}_{2} \mathrm{O} \longrightarrow 5 \mathrm{SO}_{4}^{2-}+4 \mathrm{H}^{+}+2 \mathrm{Mn}^{2+}\\ (Violet) (Colourless) \)
\(\\\underset{\text { (Yellow) }}{2 \mathrm{Fe}^{3+}}+\mathrm{SO}_{2}+2 \mathrm{H}_{2} \mathrm{O} \longrightarrow \underset{\text { (Green) }}{2 \mathrm{Fe}^{2+}}+\mathrm{SO}_{4}^{2-}+4 \mathrm{H}^{+}\)
Thus, solid A is S₈ and gas B is SO₂

\((A)=NH_{ 4 }NO_{ 2 },\ (B)=N_{ 2 },\ (C)=NH_{ 3 },\ (D)=HNO_{ 3 }\)
\(\\ NH_{ 4 }NO_{ 2 }\overset { Heat }{ \longrightarrow } \underset { (B) }{ N_{ 2 } } +2H_{ 2 }O\)
\(\\ N_{ 2 }+3H_{ 2 }\overset { Catalyst }{ \longrightarrow } \underset { (C) }{ 2NH_{ 3 } } \)
\(\\ 4NH_{ 3 }+5O_{ 2 }\longrightarrow 4NO+6H_{ 2 }O\)
\(\\ 2NO+O_{ 2 }\longrightarrow 2NO_{ 2 }\)
\(\\ 3NO_{ 2 }+H_{ 2 }O\longrightarrow 2HNO_{ 3 }+NO\)

(i) (a) CuF2 (b) (i) Cr in crO²₄ - is in the highest oxidation state, i.e., +6 while Mn in MnO is in oxidation state +6 and its most stable oxidation state is +7
(ii) due to lanthanoid contraction
(iii) [Mn²⁺ has 3d 5 configuration]

\({ \triangle }_{ t }=\left( \frac { 4 }{ 9 } \right) { \triangle }_{ 0 }\).  Thus,  \({ \triangle }_{ t }\) is smaller than \({ \triangle }_{ 0 }\).  Hence, less energy (higher wavelength) is absorbed by tetrahedral complexes than by octahedral complexes of the same metal and ligands.  Therefore, the observed colour are different.

When white light falls on the complex, some part of it is absorbed.  Greater the CFSE, greater is the energy absorbed or shorter is the wavelength absorbed \((E={hc\over\lambda })\).  The observed colour is the complementary colour of the colour absorbed.

(i) As isomer A reacts with AgNO₃ to give a white precipitate, CI must be present in the ionization sphere. As it does not react with BaCI₂, SO₄^2- must be present in coordination sphere.
Formula of A = [Co(NH₃)₅SO₄] CI (coordination no. of Co = 6) As reactions are reverse for isomer B, formula of B = [Co(NH₃)₅CI]S0₄
(ii) Ionization isomerism.
(iii) A = Pentaarnminesulphatocobalt (III) chloride ; B = Pentaamminechloridocobalt (ill) sulphate

\([Mn(CN)_6]^{3-}\)
d²sp³, (ii) inner orbital complex, (iii) paramagnetic, (iv) 2.87 B.M.
(i) d²sp³ (ii) Inner orbital complex, (iii) diamagnetic, (iv) \(\mu=0\)
(i) d²sp³, (ii) Inner orbital complex, (iii) paramagnetic, (iv) 3.87 B.M.
(i) sp³d², (ii) outer orbital complex (iii) paramagnetic (iv) 4.9 B.M.

(i) \([CoF_6]^{3-}\)
\( [Co(H_2O)_6]^{2+}\)
\([Co(CN)_6]^{3-}\)
(ii) \([FeF_6]^{3-}\)
\(\ [Fe(H_2O)_6]^{2+}\)
\([Fe(CN)_6]^{4-}\)
It is diamagnetic due to the absence of unpaired electrons.

(i) \({ NH }_{ 4 }{ NO }_{ 2 }(s)\underrightarrow { heat } { N }_{ 2 }+{ 2H }_{ 2 }O\) 
                'A'                 'B'
(ii) \({ N }_{ 2 }+{ 3H }_{ 2 }\longrightarrow 2{ NH }_{ 3 }(g)\) 
                              'C' basic
(iii) \({ 4NH }_{ 3 }+{ 5O }_{ 2 }\longrightarrow 4NO+{ 6H }_{ 2 }O\) 
\(\\ 2NO+{ O }_{ 2 }\longrightarrow { 2NO }_{ 2 }\) 
                  'D' (part of acid rain)
\({ 3NO }_{ 2 }+{ H }_{ 2 }O\longrightarrow 2{ HNO }_{ 3 }+NO\)

 \(2Pb{ { { { (NO }_{ 3 }) } } }_{ 2 }\xrightarrow { heat } 2PbO(s)+{ NO }_{ 2 }+{ O }_{ 2 }\)
                               Brown (A)
\({ 2NO }_{ 2 }(g)\overset { cooling }{ \rightleftharpoons } { N }_{ 2 }{ O }_{ 4 }(s)\)
                         (B) Colourless
\({ N }_{ 2 }{ O }_{ 4 }+2NO\overset { heat }{ \underset { 250k }{ \rightleftharpoons } } { 2N }_{ 2 }{ O }_{ 3 }(s)\)
                       (C) Blue solid

Resonating Structures of  \({ N }_{ 2 }{ O }_{ 4 }\) 

\('A'\quad is\quad { S }_{ 8 }.\quad 'B'is{ SO }_{ 2 }(g).\) 
\({ S }_{ 8 }+{ 8O }_{ 2 }\overset { heat }{ \rightarrow } { 8SO }_{ 2 }(g)\)
'B' decolorizes  
'B' turns lime water milky due to formation of  
'B' is obtained by roasting of sulphideores
'B' reduces in aqueous solution.

(i) In TLC
(ii) As adsorption incicators
(iii) In separation of inert gases.

(a) Rate of reaction is defined as change in cone. of reactants or products per unit time.Its unit is mol L^-1 S^-1.
Average rate: The rate of reaction measured over a long time interval is called average
rate of reaction: It is equal to Δx/Δt, e.g.
H₂(g) + Cl₂ (g) ⇾ 2HCI(g);
Rate of reaction = \(-{Δ[H_2]\over Δt}=-{Δ[Cl_2]\over Δt}=+{1\over 2}{Δ[HCl]\over Δt}\)
2HI (g) ⇾ H₂ (g) + I₂ (g)
Rate of reaction = \(-{Δ[HI]\over Δt}=+{Δ[H_2]\over Δt}=+{Δ[I_2]\over Δt}\)
Instantaneous rate: It is the rate of reaction when the average rate is taken over a very small interval of time. It is equal to dx/dt.
Instantaneous rate = Average rate as ∆t approaches zero.
(b) (t) Average rate = \(-\left(C_2-C_1\over t_2-t_1\right)=\left(0.17-0.31\over 60-30\right)=+{0.14\over 30}={10\over 100}\times{1\over 30}\)
= \({14\over 3}\) x 10^-3 moI L^-1 s^-1
=  4.67 x 10^-3 mol L^-1 s¹
(ii) \(k={2.303\over t}log{[A]_0\over [A]}={2.303\over 30}log{0.55\over 0.31}={2.303\over 30}[log 55-log 3]\)
\(={2.303\over 30}[1.7404 - 1.4914]={2.303\over 30}\times0.2490\)
= 1.91 x 10^-2 s^-1

At 500-800 K
\(3Fe_{ 2 }{ O }_{ 3 }+CO\rightarrow 2Fe_{ 3 }{ O }_{ 4 }+CO_{ 2 }\) 
\(Fe_{3 }{ O }_{ 4}+4CO\rightarrow 3Fe_+4CO_{ 2 }\) 
\(Fe_{ 2 }{ O }_{ 3 }+CO\rightarrow 2Fe_{ }{ O }_{ }+CO_{ 2 }\) 
At 900-1500 K
\(C+CO_{ 2 }\rightarrow 2CO\) 
\(Fe_{} { O }_{ }+CO\rightarrow Fe_{ }{ }_{ }+CO_{ 2 }\) 
\(C+O_{ 2}\rightarrow { }_{ }+CO_{ 2 }\) 
At above 1570 K
\(Fe_{} { O }_{ }+C\rightarrow Fe_{ }{ }_{ }+CO_{ }\) 
\(Ca{ CO }_{ 3 }\overset { \Delta }{ \rightarrow } Ca{ O }+CO_{ 2 }\) 
\(Ca{ O }+SiO_{ 2 }\rightarrow CaSiO_{ 3 }(slag)\) 
Ore, limestone, and coke