Chem 113 -final 2003

Universal Science College (B. Sc. Biochemistry) I First Semester 2003 Subject: Inorganic Chemistry

Full Marks: 100 Pass Marks: 50 Time: 3 hours Group - A

Answer any three questions. Questions are of equal value. 3 × 14=42 1. What is metallic bond? Discuss the crystal structure of metal and also write down the properties of metals. 2.. What do you mean by V.B.T.? Name the three type of hybrid orbital that may be formed by an atom with only s and p-orbital in its valence shell. 3. What is Radius Ratio rule? How can it help to predict the structure of an ionic crystal? 4. Define the term transition element. Discuss the trend in ionization of transition element of 3d series trend. Group - B Answer any six questions. Questions are of equal value. 6 × 7 = 42 1. Write down short note on: (i) Interstitial alloy (ii) Substitutional alloy (iii) Super conductivity 2. Use the band theory to explain the difference between conductors, insulators and semiconductors. 3. Describe how Molecular Orbital theory can be used in hetero nuclear diatomic molecules? Explain with one example. 4. What do you mean by crown and crypt? Give examples and write down its biological importance. 5. Why does Gallium show very low melting point in comparison to other elements of Group III A elements in periodic table? 6. What is stoichiometric defect in solid state? How many types of defects are there in it? 7. Discuss the electronic configuration of 3d series. 8.. How do the following properties vary in transitiion elements.: (i) Ability to form complex. (ii) Basic properties Group – C Answer any eight questions. Questions are of equal value. 8 × 2 = 16 1. Compounds of alkali metals are colourless but some compounds like K2Cr2O7, KMnO4, Na2Cr O4 are coloured. Why? 2. Why alkali metals are lighter than water? 3. Which one is more soluble NaF or CsF. Why? 4. Why O2 is paramagnetic?

5. 6. 7. 8. 9. 10. 11. 12.

Why co-valent compound are insulator? Conductivity decreases with increasing temperature but reverse in semiconductors.Why? Draw the structure of IF7 using VSEPR theory. Draw the structure of Ti O2 (Rutile structured). What is three center bond concept? Why NaI is colourless but Ag I is colored? What do you mean by complementary colour of absorbed light? Explain with an example from Transition element. Give reason for the stability of thallium in +1 oxidation state. ***

Universal Science College (B. Sc. Biochemistry) II First Semester 2003 Subject: Inorganic Chemistry

Full Marks: 100 Pass Marks: 50 Time: 3 hours Group - A

Answer any three questions. Questions are of equal value. 3 × 14=42 1. What is LCAO approximation? Discuss any two possible combination of orbital. 2. Write down the theories of bonding in metals and explain conductors, insulators and semiconductors on the basis of band theory. 3. Derive Born-Lande equation for lattice energy. Using this equation show why some crystals according to the radius ratio concept have in fact a coordination number six instead of a coordination number eight. 4. How would you define a Transition metal? Why does Transition metal compounds show its color? Explain this property with the help of first transition element series? Group - B Answer any six questions. Questions are of equal value. 6 × 7 = 42 1. What is hybridization? Define the two types of hybrid orbital that may be formed by an atom with only s and p orbital in its valence shell. 2. What do you mean by crown complexes? Explain with examples. 3. What do you mean by cohesive energy? Write down the rules about the cohesive energy and structure of metals. 4. What is Sidgwick Powell theory? How theory was developed extensively in VSEPR theory? 5. Draw the structures of CsCl and ZnS (Wurtzite structure). Showing clearly the co-ordination number of cation and anions. 6. What is inert pair effect? Discuss with the help of group III A elements of Periodic table. 7. (i) What do you mean by diamagnetism and para magnetism? (ii) How will you predict the shape of the complex with the help of magnetic moment value?

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What do you mean by variable oxidation state? Illustrate the existence of variable oxidation state in transition metals by taking example of chromium. Group – C

Answer any eight questions. Questions are of equal value. 8 × 2 = 16 1. What is super conductivity? 2. What is diagonal relationship? 3. What do you mean by nonbonding combination of orbital? 4. Conductivity decreases with increasing temperature. Why? 5. How metals have characteristics metallic luster? 6. What is organometallic compound of alkali metals? 7. What is VSEPR theory? 8. What is Frankel defect? 9. What is radius ratio? 10. "Melting points of Group III A elements do not show a regular trend as do the metal of Group I and Group II" .Why? 11. What do you mean by Ziegler – Natta catalyst? 12. Explain the stability of zero oxidation state of Ni in carbonyl. ***