csir model paper

CHEMICAL SCIENCES

This Test Booklet will contain 145 (20 Part `A‟+50 Part `B+75 Part „C‟) Multiple Choice Questions (MCQs). Candidates will be required to answer 15 in part „A‟, 35 in Part „B‟ and 25 questions in Parts C respectively ( No. of question to attempt may vary from exam to exam). In case any candidate answers more than 15, 35 and 25 questions in Parts A, B and C respectively only first 15, 35 and 25 questions in Parts A, B and C respectively will be evaluated. Questions in Parts `A‟ and „B‟ carry two marks each and Part `C‟ questions carry four marks each. There will be negative marking @25% for each wrong answer. Below each question, four alternatives or responses are given. Only one of these alternatives is the „CORRECT‟ answer to the question.

MODEL QUESTION PAPER

PART A

May be viewed under heading "General Science"

PART B

21. [CoCl4]2- shows a deep blue colour because of

1. metal to ligand charge transfer transition

2. ligand to metal charge transfer transition

3. spin allowed and Laporte forbidden d-d transition

4. spin allowed and Laporte allowed d-d transition

22. The violet colour of iodine vapour is due to

1. n-* transition

2. -* transition

3. n-* transition

4. *-* transition

23. Choose the correct statement among the following

1. diamond has lower thermal and electrical conductivities compared to graphite

2. diamond has similar thermal and electrical conductivities compared to graphite

3. diamond has higher thermal conductivity but lower electrical conductivity compared to graphite

4. diamond has the same thermal but lower electrical conductivity compared

to graphite

24. Which of the following is a nido-borane?

1. B4H10

2. B5H9

3. [B6H6]2-

4. B5H11

25. The oxidation number of sulphur in dithionite [S2O4]2- and dithionate [S2O6]2- are, respectively,

1. +3 and +4

2. +3 and +5

3. +4 and +5

4. +4 and +6

26. Among the three types of orbitals p, d, and f,

1. both p and f orbitals have centre of symmetry

2. both p and d orbitals have centre of symmetry

3. only d orbitals have centre of symmetry

4. f orbitals alone have centre of symmetry

27. The absorbance of solution having 20% transmittance is

1. 0.301

2. 0.699

3. 1.301

4. 1.699

28. The active site of enzyme nitrogenase contains

1. Mo

2. Mn

3. Fe

4. Cu

29. Which one of the following is a free radical:

1. CO

2. CN–

3. NO

4. CS

30. Choose the 16 e– complex from the following:

1. Ni(CO)4

2. Rh(PPh3)3Cl

3. Fe(CO)5

4. (6-C6H6)2Cr

31. The species having metal-metal bond is:

1. Mn2(CO)10

2. Al2(CH3)6

3. V2(O)12

4. Al2(OPri)12

32. Choose the INCORRECT statement from the following

1. Fluorine has higher electronegativity than chlorine

2. Fluorine molecule (F2) has lower bond energy than chlorine molecule (Cl2)

3. Fluorine has higher electron affinity than chlorine

4. Fluorine has a lesser tendency to form cation than chlorine

33. The only molecule having bridging oxygen is

1. Phosphorus trioxide

2. Phosphorus pentaoxide

3. Cyclic tetraphosphate

4. Pyrophosphate

34. The coordination number of phosphorus in [PMo12O40]3- is

1. 2

2. 4

3. 5

4. 6