(FREE) UPSC Current Affairs 2024 PDF

(Download) UPSC: Geo-Scientist Pre Papers-2021 (Chemistry Paper - 2)

(Download) UPSC: Geo-Scientist Pre Papers-2021

(Chemistry Paper-II)

Exam Name : UPSC Geo-Scientist and Geologist Exam

Subject : UPSC Geo-Scientist and Geologist Exam Papers 2021 : Chemistry Paper- II

Year : 2021

Chemistry Paper - II

Time Allowed : Three Hours
Maximum Marks : 200

1. The number of radial nodes for 2s, 3p and 3d orbitals, respectively are:

(a) 2, 1, 0

(b) 2, 1, 1

(d) 1, 1, 0

2. What fraction of the total number of electrons is in the p-sublevels in Iron (Fe)?

(a) 50%

(b) 49%

(d) 47.82%

3. Which is the correct order of degree of hydration among the following ions?

(a) Be²⁺ > Mg²⁺ > Sr²⁺ > Ba²⁺

(b) Be²⁺ > Sr²⁺ > Mg²⁺ > Ba²⁺

(d) Ba²⁺ > Mg²⁺ > Sr²⁺ > Be²⁺

4. Consider the following statements regarding diagonal relationship of ‘B’ and ‘Si’:
1. The electronegativity values of both the elements are almost same
2. Both the elements have almost identical values of their ionic potential
Which of the statements given above is/are correct?

(a) 1 and 2

(b) 1 only

(d) Neither 1 nor 2

5. Consider the following statements regarding Lanthanum:
1. It is a f-block element
2. It is an inner transition element
3. It is a transition series element
4. It is a rare earth metal
Which of the statements given above are correct?

(a) 1, 2, 3 and 4

(b) 2 and 4 only

(d) 1 and 3 only

6. Argon (Ar) is used in arc welding because of its:

(a) High calorific value

(b) Ability to lower the melting point of metal

(d) Flammability

7. Which one of the following represents the correct order of ionic radii among K+,S^2–, C1^–and Ca²⁺?

(a) Ca²⁺ > K⁺ > C1^– > S^2–

(b) S^2– > C1^– > K⁺ > Ca²⁺

(d) K⁺ > Ca²⁺ > S^2– > Cl^–

8. The dipole moments of H─C≡C─Cl, CO and HCl are in the directions:

(a) ←, ← and ← respectively

(b) ←, ← and → respectively

(d) ←, → and ← respectively

9. Consider the following pairs of species of oxygen and their magnetic behavior:

Which of the pair(s) of oxygen species given above represents the correct magnetic behavior?

(a) 1 only

(b) 1 and 2

(d) 2 and 4

10. Consider the following statements regarding the properties of Nitric oxide (NO):
1. Nitric oxide gas is paramagnetic but liquid nitric oxide is diamagnetic
2. Nitric oxide gas is diamagnetic but liquid nitric oxide is paramagnetic
3. Nitric oxide is a neutral oxide and is not an acid anhydride
Which of the statement(s) given above is/are correct?

(a) 1 and 3

(b) 1 only

(d) 2 only

11. Which one of the following substances has the greatest ionic character?

(a) Cl₂O

(b) NCl₃

(d) BaCl₂

12. Consider the following statements regarding Madelung constant:
Statement-1: Madelung constant typically increases with coordination number
Statement-2: Large contribution towards Madelung constant comes from nearest neighbors, and such
neighbors are more numerous when coordination number is large
Which one of the following is correct in respect of above statements?

(a) Both statement-1 and statement-2 are true and statement-2 is the correct explanation of statement-1

(b) Both statement-1 and statement-2 are true but statement-2 is not the correct explanation of statement-1

(d) Statement-1 is false but statement-2 is true

13. Which one of the following represents the correct order of melting point among BeCl2, MgCl2, CaCl2 and NaCl?

(a) BeCl₂ < MgCl₂ < CaCl₂ < NaCl

(b) MgCl₂ < BeCl₂ < CaCl₂ < NaCl

(d) BeCl₂ < CaCl₂ < MgCl₂ < NaCl

14. What kind of defect(s) appear in AgBr crystal?

(a) Schottky and Frenkel

(b) Frenkel only

(d) Metal excess defect

15. Consider the following statements:
1. N₂ molecule is paramagnetic
2. O₂ molecule is diamagnetic
3. CO⁺ has more bond order than CO
4. NO⁺ has less bond order than NO
Which of the statement(s) given above is/are correct?

(a) 1 and 4

(b) 1 and 2

(d) 2 only

16.
17. Consider the following statements:
Statement-1: KO2 is paramagnetic
Statement-2: The super oxide O₂^– is paramagnetic because it has one unpaired electron in π* 2p molecular orbital
Which one of the following is correct in respect of above statements?

(a) Both statement-1 and statement-2 are true and statement-2 is the correct explanation of statement-1

(b) Both statement-1 and statement-2 are true but statement-2 is not the correct explanation of statement-1

(d) Statement-1 is false but statement-2 is true

18. Which one of the following is NOT a resonance structure of cyanate (OCN^–)?

19. What are the spin only magnetic moments (in BM) for Ni (II) ion in a square planar and octahedral geometry, respectively?

(a) 0 (zero) and 2.83

(b) 2.83 and 0 (zero)

(d) 0 (zero) and 0 (zero)

20. Which one of the following complexes is tetrahedral as well as diamagnetic?

(a) [Ni(NH₃)_⁴] ²⁺

(b) [NiCl₄]^2–

(d) [Ni(CN)₄]^2–

21. Which one of the following will NOT precipitate AgCl while reacting with excess of AgNO₃ solution at room temperature?
(The oxidation state of cobalt (Co) in all the complexes is +3)

(a) CoCl₃.6NH₃

(b) CoCl₃.5NH₃

(d) CoCl₃.3NH₃

22. Which one of the following complexes CANNOT be ionized in solution?

(a) [Pt(NH₃)₆]Cl₄

(b) K₂[PtF₆]

(d) [Co(NH3)3Cl₃]

23. The maximum denticity of the polydentate ligand tetraethylene pentamine is equal to:

(a) 4

(b) 2

(d) 3

24. The correct IUPAC name of K₂[Zn(OH)₄] is:

(a) Dipotassium tetrahydroxo zinc (II)

(b) Potassium tetrahydroxo zinc (II)

(d) Dipotassium tetrahydroxido zincate (II)

25. Which one of the following octahedral complexes does NOT show geometrical isomerism?
(‘A’ and ‘B’ are monodentate ligands)

(a) [MA₂B₄]

(b) [MA₃B₃]

(d) [MA₅B]

26. Which one of the following will NOT show optical isomerism?

(a) [Cr(C₂O₄)₃]^3–

(b) Cis-[PtCl₂(en)₂] ²⁺

(d) [PtCl₂(NH₃)₂]

27. How many isomers are possible for [Co(en)₂Cl₂]⁺ complex ion?

(a) 1

(b) 2

(d) 4

28. Which one of the following equilibria will shift to the left in response to increase in pressure?

(a) N₂ + 3H₂ ⇋ 2NH₃ + 22.2 Kcal

(b) H₂ + I₂ + 12.4 Kcal ⇋ 2HI

(d) N₂O₄ + 14 Kcal ⇋ 2NO₂

29. The correct order of the acidic strength of H3PO4, H3PO3 and H3PO2 is:

(a) H₃PO₂ > H₃PO₃ > H₃PO₄

(b) H₃PO₄ > H₃PO₃ > H₃PO₂

(d) H₃PO₃ > H₃PO₄ > H₃PO₂

30. Which one of the following substances has highest proton affinity?

(a) H₂O

(b) NH₃

(d) CH₃COOH

31. An aqueous solution of HN3 was diluted two times, three times, four times and five times using required amount of water. Considering ‘α’ to be the ionization constant and ‘V’ as the final volume of diluted solution, choose the correct answer from the following:

(a) All the solutions will be acidic and the graph of α vs. V is non-linear

(b) All the solutions will be basic and the graph of α vs. V is non-linear

(d) All the solutions will be basic and the graph of α vs. V is linear

32. Which one of the following represents the correct order of acidity of water and alcohols?

(a) H₂O > RCH₂OH > R₂CHOH > R₃COH

(b) RCH₂OH > R₂CHOH > R₃COH > H₂O

(d) RCH₂OH < R₂CHOH < R₃COH < H₂O

33. A student calculated the pH of 10–7 M NaOH solution and 10–8 M HCl solution to be 7 and 8, respectively. To verify, the student performed experiment in laboratory using pH-meter. The instrument displays the pH of former and later solutions as 7.3 and 6.9, respectively. Choose the correct answer from the following:

(a) The pH-meter is malfunctioned and the calculation results of the student are correct

(b) The pH-meter is working properly and the calculation results of the student are incorrect

(d) The calculation results of the student are correct and the instrument is working properly only for acids

34. Which one of the following has the pH value NOT equal to one?

(a) 0.1 M HNO₃

(b) 0.05 M H₂SO₄

(d) 50 ml of 0.4 M HCl + 50 ml of 0.2 M NaOH

35. What will be the pH of a buffer solution containing 0.20 mole of NH₄OH and 0.25 mole of NH4Cl per litre?
(Dissociation constant of NH4OH at room temperature is 1.81 × 10^–5 , log1.81 = 0.2577 and log1.25 =0.0969)

(a) 9.161

(b) 9.521

(d) 9.312

36. The molarity of concentrated commercial HCl with 36 % (w/w) HCl and density 1.19 g/cm³ is close to:

(a) 11.7 M

(b) 10.6 M

(d) 11.5 M

37. Which one of the following primary standard is usually used to standardize KOH by titration?

(a) Potassium acid phthalate

(b) Sulphuric acid

(d) Nitric acid

38. While performing the titration between Mohr’s salt solution and potassium dichromate solution using diphenylamine as indicator, a student forgot to add o-phosphoric acid. Choose the correct answer from the following:

(a) The end point will be observed before the actual end point

(b) The end point will be observed after the actual end point

(d) The end point will be observed at its actual end point as there was no need to add o-phosphoric acid

39. Consider following statements in respect of titration between Ca²⁺ solution and EDTA solution using Eriochrome Black T as indicator (In):
1. The end point will be red in color
2. The end point will be blue in color
3. The end point depends on pH of solution which is controlled by adding ammonia –ammonium citrate buffer
4. The end point is observed since metal–In complex is more stable than metal–EDTA complex
Which of the statement(s) given above is/are correct?

(a) 1, 3 and 4

(b) 2, 3 and 4

(d) 2 only