3.DPP Group Theory PDF Past Paper
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Saraswati Dhaam
Saraswati Dhaam
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This document contains a past paper on group theory, specifically for a postgraduate level. It covers various concepts related to point groups and their applications. The paper features multiple-choice questions related to molecular symmetry and their associated point groups.
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## 3.DPP GROUP THEORY ### SARASWATI DHAAM® **A Quality Education Centre** 1. Select correct statement regarding C<sub>3V</sub> point group. 1. Order of the group is 6. 2. Class of the group is 3 (E, 2C<sub>3</sub> and 3σ<sub>V</sub>). 3. Number of irreducible representations 3 (A<sub>...
## 3.DPP GROUP THEORY ### SARASWATI DHAAM® **A Quality Education Centre** 1. Select correct statement regarding C<sub>3V</sub> point group. 1. Order of the group is 6. 2. Class of the group is 3 (E, 2C<sub>3</sub> and 3σ<sub>V</sub>). 3. Number of irreducible representations 3 (A<sub>1</sub>, A<sub>2</sub>, E). (A) 1 and 2 (B) 1 and 3 (C) 2 and 3 (D) 1, 2 and 3 2. "Ammonia molecule goes to inversion in configuration through transition state". What’s the point group of this at transition state : (A) C<sub>3V</sub> (B) D<sub>3V</sub> (C) D<sub>3h</sub> (D) D<sub>3d</sub> 3. D<sub>nd</sub> point group contain : (A) E, C<sub>n</sub>, nC<sub>2</sub>, ησ<sub>d</sub>, S<sub>2n</sub>, i (B) E, C<sub>n</sub>, nC<sub>2</sub>⊥ C<sub>n</sub>, ησ<sub>d</sub>, S<sub>2n</sub>, i (C) E, C<sub>n</sub>, nC<sub>2</sub>⊥C<sub>n</sub>, ησ<sub>d</sub><sup>'</sup>, S<sub>2n</sub><sup>'</sup> (D) E, C<sub>n</sub><sup>'</sup>, C<sub>2</sub><sup>'</sup>⊥C<sub>n</sub><sup>'</sup>, ησ<sub>d</sub><sup>'</sup>, S<sub>2n</sub><sup>'</sup>, i 4. [BH<sub>2</sub>]<sup>-</sup> belongs to the point group : (A) O<sub>h</sub><sup>6</sup> (B) T<sub>d</sub> (C) C<sub>2V</sub> (D) I<sub>h</sub> **Direction (Qs. 05 to 7) :** Read the following passage & give the answer of the following questions. **Passage** Trans, 1, 2 difluoroethylene molecule has a 2-fold rotational axis, a symmetry plane perpendicular to the rotational axis and an inversion centre. 5. The point group of the molecule is : (A) C<sub>i</sub> (B) C<sub>2h</sub> (C) C<sub>2V</sub> (D) D<sub>2h</sub> 6. The number of distinct symmetry operations that can be performed on the molecule is : (A) 2 (B) 4 (C) 6 (D) 8 7. Who two H atoms of the above molecule are also replaced by F atoms, the point group of the resultant molecule will be : (A) C<sub>i</sub> (B) C<sub>2h</sub> (C) C<sub>2V</sub> (D) D<sub>2h</sub> 8. Select correct statement regarding C<sub>2V</sub> point group. 1. Total number of symmetry operations (order, h) is 4. 2. Each symmetry operation is in a class. 3. Because there are 4 classes, there must also be 4 irreducible representations. 4. h = Σ [χ<sub>i</sub>(E)]<sup>2</sup> = 1<sup>2</sup> + 1<sup>2</sup> + 1<sup>2</sup> + 1<sup>2</sup> = 4 (A) 1 and 2 (B) 1, 2 and 4 (C) 2, 3 and 4 (D) 1, 2, 3 and 4. 9. Match List-I (molecule) with List-II (shape) and select the correct answer using the codes given below the lists : | List-I | List-II | |---|---| | I. P<sub>4</sub> | P. Crown | | II. S<sub>8</sub> | Q. Polymeric (Dimeric) | | III. AlCl<sub>3</sub> | R. Tetrahedral | | IV. PCl<sub>5</sub> | S. Linear | | | T. Trigonal bipyramid | (A) I-R, II-P, III-Q, IV-T (B) I-P, II-R, III-Q, IV-T (C) I-P, II-Q, III-R, IV-S (D)I-R, II-P, III-S, IV-T 10. Which of the following is an example of abelian group ? I. H<sub>2</sub>O II. NH<sub>3</sub> III. CH<sub>2</sub> = CH<sub>2</sub> (A) I only (B) II only (C) I & III only (D) II and III only. | QUE | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 1o | |---|---|---|---|---|---|---|---|---|---|---| | ANS | D | C | C | A | B | B | D | D | A | C | **27 Manav Ashram, Gopalpura Mode, Jaipur-302018** **Cell: 93144-02754** **Website: www.saraswatidhaam.com | E-mail : [email protected]** **SARASWATI DHAAM®** **A Quality Education Centre** **Page-1**
