IGNOU BCHET-147 December 2024 Previous Year Question Paper

Q1.Give the structures of chromate ion and dichromate ions. Write the reactions involved in chromy] chloride test.

Q2.Define an organometallic compound.

Q3.Differentiate between ionic and covalent sigma bonded organometallic compound _ giving suitable examples.

Q4.What is synergic effect ? How does it account for the formation of carbonyls with transition metals in low oxidation states ?

Q5.Define the term ‘hapticity’. Give the hapticity of the cyclopentadienyl groups in the following organometallic compounds, considering these compounds obey 18 electron rule : 5

(0) [Fe(CsHs)2(CO)2]

(1) Fe(CsHs)2

(iii) Mn(CsHs)(CO)s

(3)

Q6.Why is the sodium-potassium pump considered to be an example of active transport ? What is the source of energy for this pump ? With the help of a suitable diagram, explain the working of this pump.

Q7.Name the metal involved for the following biomolecules : 5

(6) Myoglobin Gi) Hemoglobin

(iii) Chlorophyll What is the most important role of each of these biomolecules ?

Q8.Name two toxic elements and give examples of two chelating agents to remove toxic elements. Which metal is responsible for itai-itai disease ? Part—B (Marks : 25)

Q9.Write the reaction and mechanism involved in the syntheses of 4-ketopentanoic acid or pentanedioic acid from ethyl-3-oxobutanoate (ethylacetoacetate).

Q10.Find out the Amax value of the following compounds : 5 CH; CH; Given : Amax values in nm for the following : Homoannular diene 253 nm

Q11.(a) Match the following functional groups with their respective stretching frequencies (any two) : 2 Functional group Frequencies (cm-!)

(b) Explain stretching vibrations for an polyatomic molecule with — suitable examples.

Q12.(a) Write the products of the following reactions : 2 Pressure

(b) Give the IUPAC names of the following compounds : 3 » COO CHy | Cl NO>

Q13.(a) Describe electronic transitions in organic molecules. 3

(b) Give the reaction of furan with maleic anhydride.

Q14.Describe band shifts arising due _ to auxochromes and types of band shifts, with suitable examples.

Q15.(a) Explain Huckel’s rule with suitable examples. 2

(b) Complete the following reactions : 3 :

(i) V205 ye

(ii) A a CH;COOHICr,0; 285 — 290 K ’

Q16.. #९(७55)2

(00))]

(ii) Fe(CsHs)2

(ii) Mn(CsHs)(CO)s

(i) “TO CH; CH; fa wa @ : frafefiad & few nm F dmx AA :

Q17.é\ )) zn/cH,CooH 020 CH; cc Cl NO;

(iii) ic

(ii) A है CH;COOH/Cr,0, 285 — 290K