Created by Kamran Fateh PPSC Analytical Chemist Final Quiz Batch 07Today marks the Final Quiz for Batch 07 of the PPSC Analytical Chemist preparation session. Best of luck to all participants—give it your best and showcase the hard work you've put in throughout the session! 1 / 100What does a higher Rf value indicate in TLC Stronger interaction with the stationary phase Weaker interaction with the stationary phase Higher molecular weight of the compound Increased retention time 2 / 100What happens when a nucleus absorbs the right amount of radio wave energy? A) It undergoes ionization B) It flips its spin state C) It gets destroyed D) It emits X-rays 3 / 100The strength of a covalent bond is generally greater when Bond length increases Bond order increases Atomic size increases Lone pairs are present on both atoms 4 / 100Which of the following is an application of gravimetric analysis? Determination of sulfate as BaSO₄ Identification of organic compounds Spectrophotometric analysis Gas chromatography 5 / 100The salt bridge in a galvanic cell is used to: Provide electrical connection Prevent polarization Maintain electrical neutrality Increase cell voltage 6 / 100Which of the following is the correct order of gravimetric analysis steps Precipitation → Digestion → Filtration → Washing → Drying → Weighing Filtration → Precipitation → Drying → Washing → Weighing Drying → Precipitation → Filtration → Washing → Digestion Washing → Drying → Precipitation → Filtration → Weighing 7 / 100. What is the effect of increasing the column temperature in GC Decreases retention time Increases retention time Increases peak broadening Does not affect separation 8 / 100D-Glucose and D-Galactose are: a) Anomers b) Epimers c) Enantiomers d) Diastereomers 9 / 100Which of the following solvents would likely move a polar compound faster in paper chromatography Water ethanol hexane acetone 10 / 100The 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 11 / 100Which condition promotes large particle growth in precipitation High supersaturation Low supersaturation Rapid addition of precipitant High stirring speed 12 / 100Commonly used detector in GC is FID UV visible Refractive index all 13 / 100Which term is NOT a state function? a) Enthalpy (H) b) Entropy (S) c) Heat (q) d) Internal energy (E) 14 / 100In 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 15 / 100The line spectrum of an element is Unique for each element The same for all elements A continuous spectrum Independent of the element’s structure 16 / 100What is the hybridization of sulfur in SF₆? sp³ sp³d sp³d² sp² 17 / 100In a fuel cell, the reactants are Continuously supplied Consumed and not replaced Solid metals None of these 18 / 100If peak tailing occurs in a GC chromatogram, what could be the possible reason? Poor injection technique Overloading of the column Contaminated stationary phase all 19 / 100Geometrical isomerism is exhibited by (a) 2-Butene (b) 2-Butyne (c) 2-Butenol (d) Butanol 20 / 100In an octahedral complex, Jahn-Teller distortion primarily affects which orbitals t2g orbitals eg orbitals Both t2g and eg orbitals equally s orbital 21 / 100Ionic bonds are formed between 2 metals 2 non metals one metal and one non metal all are correct 22 / 100Which of the following criteria is NOT necessary for a compound to be aromatic? A) Planarity B) Full conjugation of π-electrons C) Presence of an even number of π-electrons D) Obedience to Hückel’s rule 23 / 100Which base is commonly used to deprotonate terminal alkynes? a) NaOH b) NaNH2 c) KOH d) NH3 24 / 100Which law states that "the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid Henry Law Moseyle Law John Law Richard law 25 / 100Spectroscopy involves the interaction between matter and: A) Sound waves B) Electromagnetic radiation C) Magnetic fields D) Alpha particles 26 / 100What is the role of a "developing chamber" in paper chromatography To heat the sample for faster separation To maintain a saturated atmosphere of solvent vapors To provide an electric field for separation To dissolve the sample before it moves 27 / 100The protective layer of ozone is found in the: A) Troposphere B) Stratosphere C) Mesosphere D) Thermosphere 28 / 100The number of orbitals in a given subshell is determined by n 2l+1 l ml 29 / 100Carboxylic acids can be reduced to primary alcohols using: a) LiAlH₄ b) NaBH₄ c) PCC d) KMnO₄ 30 / 100Why is a selective reagent used in precipitation To ensure rapid reaction To avoid co-precipitation of unwanted species To increase the solubility of the analyte To enhance the color change 31 / 100What does a McLafferty rearrangement involve? a) Alpha cleavage b) Transfer of a γ-hydrogen via a cyclic transition state c) Simple bond cleavage d) Addition of a proton 32 / 100Which type of intermolecular force is present in all substances, regardless of their polarity Dipole-dipole interactions London dispersion forces dipole induced forces ion dipole forces 33 / 100. Which factor decreases the lattice energy of an ionic compound? Increasing the ionic charges Increasing the atomic size Increasing the number of bonds Decreasing the atomic radius 34 / 100Phenol is more acidic than alcohols due to: a) Hyperconjugation b) Resonance stabilization of the phenoxide ion c) Inductive effect of the hydroxyl group d) Steric hindrance 35 / 100Baeyer’s reagent is used to detect (a) glucose (b) double bonds (c) oxidation (d) reduction 36 / 100Chemisorption is usually: a) Reversible b) Non-specific c) Irreversible d) Multilayered 37 / 100The third law of thermodynamics states: a) Entropy of a perfect crystal at 0 K is zero b) Energy is conserved c) Enthalpy is path-independent d) Gibbs free energy must be negative 38 / 100The heat of fusion is the energy required for: a) Solid to liquid b) Liquid to gas c) Gas to solid d) Liquid to solid 39 / 100The second ionization energy of sodium (Na) is extremely high because It involves the removal of an electron from a stable noble gas configuration Sodium has a large atomic radius Sodium has a high nuclear charge The second electron is removed from the same energy level 40 / 100What is the correct IUPAC name of [Cr(en)₃]Cl₃? Tris(ethylenediamine)chromium(III) chloride Triethylenediaminechromium(III) chloride Chromium(III) ethylenediamine chloride None 41 / 100In which of the following scenarios is Gay-Lussac’s Law most applicable A hot air balloon rising A syringe being pulled back A tire pressure increasing in the summer A gas-filled balloon expanding 42 / 100The titration of Zn²⁺ with EDTA is best performed at what pH? 3 7 10 13.3 43 / 100The process of allowing a precipitate to stand in solution before filtration is called Drying digestion adsorption elution 44 / 100What is the principal quantum number (n) for the first excited state of a hydrogen atom? 0 1 2 3 45 / 100In a titration curve, what does the steepest region indicate The buffer region The half-equivalence point The equivalence point he starting pH 46 / 100In a titration of calcium with EDTA, which buffer is commonly used Acetate buffer Phosphate buffer Ammonia-ammonium chloride buffer Borate buffer 47 / 100What is the characteristic flame color for potassium salts in a flame test? yellow green red violet 48 / 100Which of following ligands make the most stable complexes among following NH3 H2O en CN- 49 / 100Why is primary carbocation formation avoided in Friedel–Crafts alkylation? A) Primary carbocations are too stable B) Primary carbocations undergo rearrangement C) Alkyl halides cannot ionize in the presence of AlCl₃ D) The reaction is too slow with primary carbocations 50 / 100The purpose of a porous frit in a salt bridge is to: a) Increase resistance b) Allow ion migration c) Block electron flow d) Filter impurities 51 / 100Le 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 52 / 100Which noble gas can form stable compounds by violating the octet rule He Kr Ne Xe 53 / 100Electrogravimetry involves Precipitation by an electric current Filtration under vacuum Volatilization of the analyte Complexometric titration 54 / 100Which 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 / 100Which of the following reagents is used to convert an alkyne to a cis-alkene? a) H2/Pt b) H2/Lindlar’s catalyst c) Na/NH3 d) BH3 56 / 100Which of the following statements about EDTA is incorrect? It forms a 1:1 complex with most metal ions It has four carboxylate groups It has two amine groups It is only soluble in acidic solutions 57 / 100If a compound does not move from the baseline in TLC, what could be the reason The compound is highly polar and strongly adsorbed to the stationary phase The solvent is too polar The compound is volatile and evaporated The TLC plate was overheated 58 / 100The Tyndall effect is observed in: a) True solutions b) Colloidal solutions c) Suspensions d) Both b) and c) 59 / 100A buffer solution contains A strong acid and its salt A weak acid and its conjugate base A strong base and a strong acid A strong base and its conjugate acid 60 / 100What is the product of the Wolff-Kishner reduction of acetophenone? a) Ethylbenzene b) Toluene c) Benzene d) Phenol 61 / 100What does the peak current in cyclic voltammetry depend on Scan rate Temperature pH All 62 / 100 The order of a reaction can be determined by Stoichiometric coefficients Experimental data Molecularity none 63 / 100In a two-dimensional paper chromatography setup, why is the paper rotated 90° before the second run To improve separation of overlapping spots To increase the Rf values To ensure all compounds move to the same position To dry the paper before re-running the experiment 64 / 100Which 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 65 / 100The 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 66 / 100Only radioactive lanthanide elements is La Cm Pm Gd 67 / 100During electrolysis of molten NaCl, the product formed at the cathode is: a) Chlorine gas b) Sodium metal c) Hydrogen gas d) Oxygen gas 68 / 100 Which of the following factors affects UV absorption? A) Conjugation B) Molecular weight C) pH of the solvent D) Both A and C 69 / 100Which of the following is NOT a commonly used IR light source in IR spectroscopy? A) Nernst Glower B) Tungsten filament C) Globar (Silicon Carbide Rod) D) Incandescent wire 70 / 100Ozonolysis of benzene gives Glycol Formaldehyde Acetaldehyde Glyoxal 71 / 100How many stereoisomers are possible for 1,2-dichlorocyclohexane? 1 2 3 4 72 / 100Find the compound with the highest boiling point among the following (a) n-Butane (b) n-Octane (c) Iso-octane (d) 2,2,3,3-Tetramethylbutane 73 / 100What is the base peak in a mass spectrum? a) The heaviest ion b) The tallest peak representing the most abundant ion c) The smallest ion d) The peak with the highest m/z ratio 74 / 100Which of the following solvents is best for E1 reactions? a) Polar protic b) Polar aprotic c) Non-polar d) Aprotic 75 / 100The 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 76 / 100Which of the following is NOT a polar aprotic solvent? a) DMSO b) DMF c) Acetone d) Water 77 / 100According to SHAB theory, which type of interactions are most stable Hard acid with hard base Hard acid with soft base Soft acid with hard base Random interactions 78 / 100What is the confirmatory test for calcium (Ca²⁺) ions? Ammonium molybdate test White precipitate with ammonium oxalate Formation of brown ring Blue solution with sodium hydroxide 79 / 100A capillary column in GC typically has A packed solid stationary phase A thin liquid stationary phase coated on the inner wall A length of less than 1 meter An internal diameter > 5 mm 80 / 100In a bomb calorimeter, the heat transfer is measured under: a) Constant volume b) Constant pressure c) Variable temperature d) Variable pressure 81 / 100In paper chromatography, what is the primary force that helps separate components Gravity Capillary action Centrifugal force Electromagnetic force 82 / 100In a reaction where ΔG = 0, which of the following is true? The reaction is spontaneous The reaction will stop The equilibrium constant is zero The reaction is at equilibrium 83 / 100Which reagent is used to detect ammonium (NH₄⁺) ions? Sodium hydroxide (NaOH) Barium chloride (BaCl₂) Silver nitrate (AgNO₃) Potassium dichromate (K₂Cr₂O₇) 84 / 100. If n=3, what are the possible values of l 0, 1, 2, 3 0, 1, 2 1, 2, 3 -3 to +3 85 / 100Which of the following is true about the SN2 mechanism? a) It is a two-step process b) It involves a carbocation intermediate c) It is a concerted mechanism d) It is favored by tertiary alkyl halides 86 / 100Photochemical smog is also called: A) Reducing smog B) Oxidizing smog C) Industrial smog D) Acid smog 87 / 100What is the relationship between cis-2-butene and trans-2-butene? a) Enantiomers b) Diastereomers c) Identical d) Constitutional isomers 88 / 100What is the role of a Hollow Cathode Lamp (HCL) in AAS? A) It absorbs light from the sample B) It emits light specific to the element being analyzed C) It provides thermal energy for atomization D) It detects the intensity of absorbed light 89 / 100Gravimetric analysis is considered a fundamental method in classical analytical chemistry because of its High accuracy and precision Rapid results Use of expensive equipment Ability to detect trace elements 90 / 100What is the major product of the E2 elimination of 2-bromo-2-methylbutane with NaOH? a) 2-methyl-1-butene b) 2-methyl-2-butene c) 1-butene d) 2-butene 91 / 100In AAS, what does the monochromator do? A) It isolates the specific wavelength absorbed by the analyte B) It amplifies the signal for better detection C) It converts electrical signals into concentration values D) It burns the sample for atomization 92 / 100The decay of 238U to 206Pb involves the emission of how many alpha particles? 6 8 10 12 93 / 100Total elememts in halogen family 4 5 6 7 94 / 100What is the primary basis of gravimetric analysis Color change of the analyte Electrical conductivity of the solution Measurement of the mass of the analyte Change in temperature 95 / 100What is the purpose of drying or ignition in gravimetric analysis To dissolve the precipitate To remove moisture and volatile impurities To increase the solubility of the analyte To facilitate filtration 96 / 100What is the molecular geometry of SF₄ according to VSEPR theory Tetrahedral Trigonal bipyramidal Square planar See-saw 97 / 100What is the formula for calculating the Rf value Distance traveled by solvent / Distance traveled by solute Distance traveled by solute / Distance traveled by solvent Distance traveled by solute × Distance traveled by solvent Distance traveled by solvent – Distance traveled by solute 98 / 100Physical adsorption is characterized by: a) Strong chemical bonds b) Van der Waals forces and reversibility c) Formation of monolayers d) High specificity 99 / 100Denaturation of proteins disrupts: a) Primary structure b) Secondary and tertiary structures c) Only quaternary structure d) Covalent bonds in the backbone 100 / 100The term "BOD" stands for: A) Biological Oxygen Demand B) Basic Oxygen Demand C) Biodegradable Organic Debris D) Biochemical Oxygen Depletion Your score isThe average score is 78% 0% Restart quiz
