Ncert Solutions Chemistry Class 12th

4.9 Given-

Energy of activation, E_a= 209.5 kJ mol^–1

E_a in joules = 209.5 * 1000 = 209500 J mol^–1

Temperature, T = 581K

Gas constant, R = 8.314 J K^-1 mol^-1

Using the Arrhenius equation,

k = Ae^-Ea/RT

In this equation, the term e^-Ea/RT represents the number of molecules which have kinetic energy greater than the activation energy, E_a.

∴The number of molecules = e^-Ea/RT → Equation 1. Substituting all the known values in equation 1, we get,

= e^{-209500/8.314X581}

=e^-43.3708

Finding the value of anti ln (43.3708), we get, 1.47 * 10^-19

The fraction of molecules of reactants having energy equal to or greater than activation energy is 1.47 * 10^-19

Isomers are the compounds which have same chemical formula but different arrangement of atoms in space. There are principle two types of isomerism:

(i) Stereo isomerism

(ii) Geometrical isomerism

(iii) Optical isomerism

(iv) Structural isomerism

(v) Ionisation isomerism

(vi) Linkage isomerism

(vii) Coordination isomerism

(viii) Solvate isomerism

Geometrical isomerism comes into existence by the different spatial arrangement of groups around the central metal atom. Similar groups may either be arranged on the same side or on opposite sides of the central metal atom. This gives rise to two types of isomers called cis and trans isomers. When groups under consideration are arranged on the same side of the central metal atom, isomers are called cis isomers and when the groups under consideration are spatially placed on the opposite sides, isomers are called trans isomer.

(i) Starting with cation, the complex ion contains six ammonia molecules with cobalt in + 3 oxidation The name of compound: [Co (NH₃)₆]Cl₃ is hexaamminecobalt (III) chloride.

(ii) The complex ion is cation, so there are 2 ammonia molecules, one chloride ion and methyammine molecule qith platinum in + 2 state. Going in alphabetical order, the name of compound: [Pt (NH₃)₂Cl (NH₂CH₃)]Cl is diamminechloridomethylammineplatinum (II)

(iii) It is a complex cation with six water molecules and titanium atom in + 3 state. The name of the compound: [Ti (H₂O)₆]³⁺ is hexaaquatitanium (III) ion

(iv) The complex ion is cation with cobalt in + 3 state and with four ammonia molecules etetraammine, one chloride ion and nitrate ion. The name of the compound: [Co (NH₃)₄Cl (NO₂)]Cl is tetraamminechloridonitritocobalt (III) chloride.

(v) The complex ion is cation with manganese in + 2 state and six water The name of compound: [Mn (H₂O)₆]²⁺ is hexaaquamanganese (II) ion.

(vi) The complex is anion with nickel in + 2 state and with four chloride ions. The name of the compound: [NiCl₄]^2– is tetrachloridonickeltate (II)

(vii) The complex is cation with nickel in + 2 state and six ammonia molecules. The name of compound: [Ni (NH₃)₆]Cl₂ is hexaamminenickel (II) chloride.

(viii) The complex is cationwithcobalt in + 3 stateand there is a bidentate ligand called as The name of compound : [Co (en)₃]³⁺ is tris (ethylenediamine)cobalt (III) ion.

(ix) It is neutral complex with four carbonyl molecules and cobalt in 0 state. The name of compound: [Ni (CO)₄] is tetracarbonylcobalt (0).

(i) Tetrahydroxidozincate (II) = [Zn (OH)₄]^-2

Tetrahydroxi means 4 hydroxide ions with zinc in + 2 oxidation state. Hydroxide ions have a negative charge of -1, so balancing the overall charge of the coordination compound to be zero we get the formula as : [Zn (OH)₄]^-2

(ii) Potassium tetrachloridopalladate (II) = K₃ [PdCl₄].

Tetrachlorido means 3 Chloride ions each having a negative charge. Platinum is in + 2 state. Balance overall charge as 0, no. Of potassium ions are 3. Formula: K₃ [PdCl₄].

(iii) Diamminedichloridoplatinum (II) = [Pt (NH₃)Cl₂]²⁺

Diammine means 2 ammonia molecules, dichlorido means 2 chloride ions, platinum in + 2 state. Formula: [Pt (NH₃)Cl₂]²⁺

(iv) Potassium tetracyanidonickelate (II) = K₂ [Ni (CN)₄].

tetracyanido means 4 cyanide ions each with a unit negative charge and nickel atom with + 2 state. Formula: K₂ [Ni (CN)₄].

(v) Pentaamminenitrito-O-cobalt (III) = [Co (ONO) (NH₃)₅]⁺²

penataammine means 5 ammonia molecules, nitrito-O means nitrate ion which is bonded to central atom via oxygen and cobalt in + 3 state. Formula: [Co (ONO) (NH₃)₅]⁺²

(vi) Hexaamminecobalt (III) sulphate = [Co (NH₃)₆]₂ (SO₄)₃

Hexaammine means six ammonia molecules and cobalt in + 3 state. Sulphate have a negative charge of-2 Balance overall charge as 0. Formula: [Co (NH₃)₆]₂ (SO₄)₃

(vii) Potassium tri (oxalato)chromate (III) = K₃ [Cr (C₂O₄)₃].

trioxolato means 3 oxolate ions and chromium in + 3 state. Balance overall charge as 0. Formula: K₃ [Cr (C₂O₄)₃].

(viii) Hexaammineplatinum (IV) = [Pt (NH₃)₆]⁴⁺

hexaammine means 6 neutral ammonia molecules and platinum in + 4 state. Balance overall charge as 0. Formula: [Pt (NH₃)₆]⁴⁺

(ix) Tetrabromidocuprate (II) = [Cu (Br)₄]^2-

tetrabromido means 4 bromide ions with a unit negative charge each and copper in + 2 state. Balance overall charge as 0. Formula: [Cu (Br)₄]^2-

(x) Pentaamminenitrito-N-cobalt (III) = [Co (NO₂) (NH₃)₅]²⁺

pentaammine means 5 neutral ammonia molecules, nitrito-N means nitro group bonded to central atom via the lone pair of electron of nitrogen and cobalt in + 3 state. Balance overall charge as 0. Formula: [Co (NO₂) (NH₃)₅]²⁺

(i) Let Oxidation of Co be x and charge on the complex is given as + 2

H₂O has Oxidation Number: 0

CN has Oxidation Number: -1

en has Oxidation Number :0

 

(ii) Let Oxidation number of Co be x and charge on the complex is given as + 1

Br has Oxidation number: 1

en has oxidation number : 0

 

(iii) Let Oxidation number of Pt be x and charge on the complex is given as -2

Cl has oxidation number : -1

 

(iv) This complex can also be seen as [Fe (CN)₆]^3-

Let Oxidation number of Fe be x and charge given on the complex is given as -3

CN has oxidation number : -1

(v) Let Oxidation number of Cr be x and charge given on the complex is given as 0

NH₃ has oxidation number : 0

Cl has oxidation number: -1