0 votes, 0 avg 208 Created by Sana Kaussar PPSC Analytical Chemistry Demo Quiz Batch 08Today's demo quiz for PPSC Analytical Chemist Batch 08 consists of 60 MCQs with a 30-minute time limit. Cheating is strictly prohibited, as honesty is a core teaching of Islam. Success earned through hard work and dedication is truly rewarding, while dishonesty leads to nothing but loss. Success comes through hard work and integrity. Best of luck to all participants! 1 / 60Strongest acid in chemistry is HCl H2SO4 HNO₃ HClO4 2 / 60The conjugate base of HSO4− is SO42− H2SO4 H3O+ HSO3− 3 / 60Jahn-Teller distortion in an octahedral complex arises due to Electronic repulsions in fully filled d-orbitals Removal of degeneracy in orbitals to lower energy Steric effects of large ligands High oxidation state of the metal 4 / 60. Which of the following electronic configurations is most likely to show Jahn-Teller distortion in an octahedral complex d³ d⁵ (high spin) d⁷ (high spin) d⁹ 5 / 60Which of the following factors does NOT affect the magnitude of crystal field splitting (Δ₀) in octahedral complexes? The nature of the metal ion The oxidation state of the metal The geometry of the complex The ionic radius of counterions 6 / 60Which of the following is an example of an ambidentate ligand? NH₃ CN⁻ H₂O CO 7 / 60Which of the following statements about Werner’s theory of coordination compounds is incorrect? Primary valency corresponds to oxidation state Secondary valency determines the coordination number Secondary valency can be ionizable Ligands satisfy both primary and secondary valencies 8 / 60In which of the following complexes does the central metal atom have a coordination number of 4 but does NOT adopt a tetrahedral geometry? [NiCl₄]²⁻ [Cu(NH₃)₄]²⁺ [PdCl₄]²⁻ [Zn(NH₃)₄]²⁺ 9 / 60Transition series start from which period of periodic table 2 3 4 5 10 / 60Which of following has greatest electron affinity? F Cl Br I 11 / 60How many valence electrons are present in the Lewis structure of NO₃⁻ (nitrate ion)22 22 24 26 32 12 / 60Which of the following has the lowest pH? Baking soda solution pure milk water lemon juice 13 / 60The Usanovich concept is considered the most general because it includes Only Arrhenius and Bronsted-Lowry theories Only Lewis theory All other acid-base concepts including oxidation-reduction reactions Only acid-base neutralization reactions 14 / 60A buffer solution is most effective when The pH = pKa The pH = 7 The base is much greater than the acid The acid is much greater than the base 15 / 60Outer orbital complexes are shown by weak field ligands strong field ligands both strong and weak field ligands by neutral compounds 16 / 60Which transition metal is commonly used in making stainless steel? Copper chromium nickel iron 17 / 60The orthorhombic crystal system has Three equal axes, all at right angles Three unequal axes, all at right angles Three unequal axes, with one angle different from 90° One unique axis among three equal axes 18 / 60What happens to the temperature of a liquid while it is boiling It increases continuously It decreases continuously Remains constant It fluctuates 19 / 60Why does a hot air balloon rise? The air inside the balloon becomes denser The heated air inside the balloon expands and becomes less dense The external pressure decreases The number of air molecules inside the balloon increases 20 / 60The total number of orbitals in the third energy level (n=3n=3n=3) is 3 4 9 7 21 / 60. Which detector is the most sensitive for detecting organic compounds in GC? Flame Ionization Detector (FID) Thermal Conductivity Detector (TCD) Electron Capture Detector (ECD) UV-Vis Detector 22 / 60Which injection method is used for analyzing thermally unstable compounds in GC? Split injection Splitless injection On-column injection Flash vaporization 23 / 60Which resin type is most suitable for strong anion exchange chromatography Sulfonic acid resins Carboxyl resins Quaternary ammonium resins Hydroxylated silica resins 24 / 60A green residue observed after performing the charcoal cavity test indicates the presence of: Fe Ba Cu Mn 25 / 60Which of the following acid radicals can be detected using a ferric chloride (FeCl₃) test? Acetate (CH₃COO⁻) Carbonate (CO₃²⁻) Sulfate (SO₄²⁻) Nitrate (NO₃⁻) 26 / 60What is the confirmatory test for phosphate (PO₄³⁻) ions Brown ring test White precipitate with ammonium molybdate Effervescence with acid Yellow precipitate with AgNO₃ 27 / 60In the group analysis of basic radicals, which cations are precipitated as chlorides in Group I? Na⁺, K⁺ Pb²⁺, Hg₂²⁺, Ag⁺ Fe²⁺, Fe³⁺ Cu²⁺, Zn²⁺ 28 / 60Which reagent is used to detect ammonium (NH₄⁺) ions? Sodium hydroxide (NaOH) Barium chloride (BaCl₂) Silver nitrate (AgNO₃) Potassium dichromate (K₂Cr₂O₇) 29 / 60The cobalt nitrate test is used to identify which type of compounds Carbonates and nitrates Halides Phosphates and aluminum compounds Sulfates 30 / 60Why is Volhard’s method performed in an acidic medium? To prevent hydrolysis of Ag⁺ To ensure complete precipitation of AgCl To keep Fe³⁺ in solution To increase the solubility of the precipitate 31 / 60What is the major limitation of the Mohr method? It cannot be used in acidic solutions It requires a colored indicator It is only applicable to sulfate ions It requires an external indicator 32 / 60Which of the following indicators is commonly used in the Mohr method of precipitation titration Methyl orange Fluorescein Dichlorofluorescein Potassium chromate 33 / 60In complexometric titrations, why is a buffer used To maintain the solubility of the metal complex To adjust the pH for maximum complex stability To oxidize metal ions To precipitate interfering ions 34 / 60Which of the following reactions is characteristic of alkanes? a) Electrophilic substitution b) Nucleophilic addition c) Free radical substitution d) Elimination 35 / 60Which of the following is the most reactive towards electrophilic substitution? a) Benzene b) Toluene c) Nitrobenzene d) Chlorobenzene 36 / 60Which of the following alkyl halides will undergo SN2 reaction most readily? a) Tertiary butyl bromide b) Isopropyl chloride c) Methyl iodide d) Neopentyl bromide 37 / 60Which of the following conditions favors an E2 mechanism? a) Weak base and polar protic solvent b) Strong base and polar aprotic solvent c) Weak base and polar aprotic solvent d) Strong base and polar protic solvent 38 / 60Lucas reagent is used to distinguish between: a) Primary, secondary, and tertiary alcohols b) Alcohols and phenols c) Aldehydes and ketones d) Alkanes and alkenes 39 / 60Williamson ether synthesis involves: a) Reaction of an alkoxide ion with an alkyl halide b) Dehydration of alcohols c) Oxidation of alkenes d) Hydrolysis of esters 40 / 60Which reagent is used to distinguish between aldehydes and ketones? a) Fehling's solution b) Tollens' reagent c) Both a and b d) Lucas reagent 41 / 60The strongest acid among the following is: a) Formic acid b) Acetic acid c) Chloroacetic acid d) Benzoic acid 42 / 60Carboxylic acids can be reduced to primary alcohols using: a) LiAlH₄ b) NaBH₄ c) PCC d) KMnO₄ 43 / 60Which of the following is true for enantiomers? a) They have the same melting point b) They rotate plane-polarized light in opposite directions c) They have the same boiling point d) All of the above 44 / 60Which of the following statements is true about the Beer-Lambert law? a) It is only applicable to UV-Vis spectroscopy b) It assumes monochromatic light c) It is not valid for dilute solutions d) It does not depend on the path length 45 / 60Bragg's law is given by the equation: a) nλ = 2d sinθ b) E = hν c) c = λν d) ΔE = hc/λ 46 / 60In XRD, the intensity of the diffracted beam depends on: a) The atomic number of the atoms b) The crystal structure c) The wavelength of the X-rays d) All of the above 47 / 60In mass spectrometry, the base peak corresponds to: a) The peak with the highest m/z value b) The peak with the lowest m/z value c) The most intense peak in the spectrum d) The peak representing the molecular ion 48 / 60The splitting pattern of a proton signal in ^1H NMR is determined by: a) The number of adjacent protons b) The applied magnetic field c) The chemical shift d) The relaxation time 49 / 60Which of the following factors does NOT affect the vibrational frequency of a bond in IR spectroscopy? a) Bond strength b) Mass of the atoms c) Polarity of the bond d) External magnetic field 50 / 60Which of the following transitions is responsible for absorption in the UV-Vis region? a) σ → σ* b) n → π* c) π → π* d) Both b and c 51 / 60The van't Hoff factor (i) for a 0.1 M solution of K₃[Fe(CN)₆] assuming complete dissociation is: 1 2 3 4 52 / 60Le Chatelier's principle predicts that increasing the pressure of the system 2SO2(g)+O2(g)⇌2SO3(g)will: a) Shift the equilibrium to the left b) Shift the equilibrium to the right c) Have no effect on the equilibrium d) Increase the temperature 53 / 60The half-life of a first-order reaction is 10 minutes. What is the rate constant (k) for the reaction? a) 0.0693 min⁻¹ b) 0.693 min⁻¹ c) 6.93 min⁻¹ d) 69.3 min⁻¹ 54 / 60Which of the following electrodes is commonly used as a reference electrode in voltammetry? a) Glass electrode b) Calomel electrode c) Platinum electrode d) Gold electrode 55 / 60In potentiometric titrations, the equivalence point is determined by: a) A sudden change in pH b) A sudden change in conductivity c) A sudden change in potential d) A sudden change in temperature 56 / 60During electrolysis of molten NaCl, the product formed at the cathode is: a) Chlorine gas b) Sodium metal c) Hydrogen gas d) Oxygen gas 57 / 60The half-life of a radioactive isotope is 5 years. What fraction of the original sample will remain after 15 years? a) 1/2 b) 1/4 c) 1/8 d) 1/16 58 / 60A reaction has a rate constantk=2.3×10−3 s−1at 25°C. What is the order of the reaction? a) Zero order b) First order c) Second order d) Third order 59 / 60The decay of 238U to 206Pb involves the emission of how many alpha particles? 6 8 10 12 60 / 60Which of the following solutions will have the highest boiling point? a) 0.1 M NaCl b) 0.1 M glucose c) 0.1 M CaCl2 d) 0.1 M AlCl3 Your score isThe average score is 57% 0% Restart quiz
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