IGNOU BCHCT-137 December 2023 Previous Year Question Paper

Q1.Attempt any two parts : 2.5*x2=5

(a) Why are zinc and cadmium soft ?

(b) Which of these is coloured and why :

Q2.3.

(c) Why are the second ionisation enthalpies of chromium and copper higher than expected ?

Q3.Discuss the ways in which the actinoids resemble their lanthanoid congeners.

Q4.What is lanthanoid contraction ? Give an important consequence of this.

Q5.(a) Determine the coordination number and oxidation state of the central metal in @ [Fe(CN), |” and Gi) [Pt(NHg), Cl]. 3

(b) Write the IUPAC names of any two of the following : 2 Gi) Ke[ Ni(CN), | Gii) [Co(NH3), |Brs

Q6.(a) Label the following ligands as monodentate, bidentate, ambidentate or polydentate (any three) :

Q7.Trimethyl phosphene-PMe3 Gi) 1, 2-diaminoethane-en

(iii) Nitrite- NOZ

(iv) EDTA

(b) Write the formulae of the following : 2 @ Potassium trioxalatoferrate (II) Gi) p-dihydroxidobis {tetraamine cobalt (IID} nitrate

Q8.(a) Mention the isomerism depicted in the following pairs : 1x2=2 @) [Pt (NH3)4 Clz] Br2 and [Pt (NHs3)4 Bre] Cle

(ii) [Co (NHs)«] [Cr (CN)«] and [Cr (NHs3)6] [Co (CN)6]

(b) Using VBT, predict the hybridization, geometry and number of unpaired electrons in [Cr (NH3)6] .

Q9.(a) What would be the CFSE for an octahedral complex of a d’ ion in weak field and strong field ? 4

(b) Mention one important compound in bioinorganic chemistry containing iron.

Q10.For the low spin complex [Fe (en)s] Cls, find: 5

(i) the oxidation number of iron

(ii) the geometry of the complex

(iii) whether it is diamagnetic or paramagnetic

(iv) the number of unpaired electrons in the complex Part—B (Marks : 25)

Q11.(a) Write down van der Waals equation and explain volume correction and pressure correction terms briefly. 2

(b) State law of corresponding states and write its equation.

Q12.(a) Define an ideal gas. Derive the expression for ideal gas equation. 3

(b) What do you understand by mean free path ? Derive its mathematical formula and explain all the terms.

Q13.(a) Explain three characteristic properties of liquids and discuss their importance. 3

(b) Discuss the effect of temperature on viscosity of liquids and draw the nature of plot between log yn and कक

Q14.(a) Explain the characteristics of ionic solids and suggest any two examples for the same. 3

(b) What are crystal systems ? Give the relationship between their axes and angle for a cubic system.

Q15.(a) Draw the structures of unit cells of CsCl, NaCl and ZnS. 3

(b) Write briefly about liquid crystals. Also give structure of an organic compound that is liquid crystal.

Q16.(a) What do you understand by zeroth order of reaction ? Explain with a suitable example. Draw the nature of plot of integrated rate law for zero order reaction. 3

(b) First order rate constant for the decomposition : 2N,0; — 4NO, + Og at 340 K is 5.20 x 10° s"!. Calculate the time required to reduce concentration of N20; to its half.

Q17.Explain activated complex theory with the help of graphical representation of change in potential energy. Discuss about energy requirement for the reaction.

Q18.1. 0.

Q19.(क)6) [Fe(CN), | और Gi) [Pt(NH5), Cly |

(i) K2[Ni(CN), ] Gii) [Co(NH3), |Bry

(iv) EDTA

Q20.[Pt (NHs)4 Cho] Br2 4 [Pt (NH3)4 Br2] Cle Gi) [Co (NHs)s] [Cr (CN)e] व [Cr (NHs)e] [Co (CN)s]

Q21.1. 0.

Q22.1. 0.