PPSC Analytical Chemist BS-17 Demo Test

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This test consists of 50 questions with a 30-minute time limit. Ensure a fair attempt, as cheating is strictly prohibited and goes against Islamic teachings. Read each question carefully, select the best answer, and submit before time runs out. Once submitted, answers cannot be changed.

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Created on February 06, 2025 By

Kamran Fateh

Chemical Symbols and Formulae for Elements and Compounds Education Presentation in 0 Flat Graphic Flat Cartoon Style

PPSC Analytical Chemist BS-17 Demo Test

1 / 50

The van Deemter equation in HPLC describes the relationship between

1) Mobile phase flow rate and peak area

2) Column efficiency and particle size

3) Theoretical plates and retention time

4) Mobile phase viscosity and resolution

2 / 50

Which of the following factors affect the value of for a reaction?

1) Catalyst

2) Temperature

3) Volume

4) Pressure

3 / 50

Which type of solution will have a concentration below the saturation point?

1) Supersaturated solution

2) Unsaturated solution

3) Saturated solution

4) All

4 / 50

Calculate the root mean square velocity of oxygen gas at 300 K.

1) a) 483 m/s

2) b) 320 m/s

3) c) 615 m/s

4) d) 220 m/s

5 / 50

Which of the following factors does NOT affect the separation of compounds in gas chromatography

1) Column temperature

2) Carrier gas flow rate

3) Sample injection volume

4) Wavelength of UV light

6 / 50

In the Mohr,s method of precipitation titration, indicator used is

1) floroscein

2) ferric alum

3) 5% K2CrO4

4) none of these

7 / 50

The strongest type of intermolecular force present in solid CO₂ (dry ice) is

1) Hydrogen bonding

2) Dipole-dipole interactions

3) London dispersion forces

4) Ionic bonding

8 / 50

Which of the following salts will produce an acidic solution when dissolved in water

1) NaCl

2) NH4Cl

3) K₂CO₃

4) Na2SO4

9 / 50

In High-Performance Liquid Chromatography (HPLC), the most common detector used is:

1) a) UV-Vis Detector

2) b) IR Detector

3) c) X-ray Fluorescence

4) d) Mass Spectrometer

10 / 50

Which of the following reagents is best for the selective oxidation of benzyl alcohol to benzaldehyde?

1) a) KMnO₄

2) b) PCC

3) c) LiAlH₄

4) d) NaBH₄

11 / 50

Which solvent favors SN2 reactions?

1) a) Water

2) b) Ethanol

3) c) DMSO

4) d) Acetic acid

12 / 50

Which of the following does not give a positive iodoform test?

1) a) Acetone

2) b) Acetaldehyde

3) c) 2-Butanone

4) d) Formaldehyde

13 / 50

Which of the following is a biodegradable polymer?

1) a) Nylon-6,6

2) b) Polylactic acid (PLA)

3) c) Teflon

4) d) Polyethylene

14 / 50

EDTA forms a complex with metal ions at:

1) a) Low pH

2) b) High pH

3) c) Neutral conditions

4) d) In presence of chloride ions

15 / 50

Greenhouse gases include:

1) a) CO2 , 𝐶 𝐻4 , 𝑁2O

2) b) 𝑂2 , 𝑁2

3) c) 𝐴 𝑟, He

4) d) 𝑁𝐻3, 𝐻𝐶 𝑙

16 / 50

Reverse-phase HPLCuses:

1) a) A polar stationary phase

2) b) A non-polar stationary phase and polar mobile phase

3) c) A non-polar mobile phase

4) d) A gas as mobile phase

17 / 50

Which reagent can be used to distinguish between phenol and alcohols?

1) a) Lucas reagent

2) b) Br₂ water

3) c) HCl

4) d) NaOH

18 / 50

Which molecule has the highest bond energy?

1) a) 𝑁 2

2) b) 𝑂 2

3) c) 𝐻 2

4) d) 𝐶 𝑙 2

19 / 50

Which of the following graphs correctly represents the pH change when a weak acid is titrated with a strong base

1) A sharp pH rise at the equivalence point

2) A gradual pH rise, followed by a steep increase at the equivalence point

3) A steady pH rise with no significant jumps

4) A sharp pH drop at the equivalence point

20 / 50

The dead volume in an HPLC system refers to

1) The volume of solvent required to dissolve the sample

2) The volume of mobile phase inside the column

3) The volume of mobile phase in the system before reaching the detector

4) The void space in the stationary phase

21 / 50

The Langmuir adsorption isotherm assumes:

1) a) Multilayer adsorption

2) b) Monolayer adsorption

3) c) No adsorption

4) d) Unlimited adsorption

22 / 50

The flame test color for potassium ion is:

1) Green

2) Violet

3) Yellow

4) Blue

23 / 50

In capillary columns used in gas chromatography, the stationary phase is typically

1) A solid adsorbent packed in the column

2) A liquid coated onto the inner wall of the column

3) A gas that interacts with the analytes

4) A metal surface used to catalyze reactions

24 / 50

Which of the following is an example of a Lewis acid?

1) BF3

2) H2O

3) NH3

4) OH-

25 / 50

Carrier gases used in Gas Chromatography (GC) must be:

1) a) Reactive

2) b) Non-reactive and pure

3) c) Heavy and dense

4) d) Condensable

26 / 50

The best filter medium for collecting fine precipitates in gravimetric analysis is

1) Filter paper

2) Sintered glass crucible

3) Cotton wool

4) Polyethylene membrane

27 / 50

Which reaction order has a constant half-life?

1) a) First-order

2) b) Second-order

3) c) Zero-order

4) d) Third-order

28 / 50

Which of the following does not undergo Friedel-Crafts alkylation?

1) Benzene

2) Toluene

3) Aniline

4) Chlorobenzene

29 / 50

Highest electron affinity among following is

1) F

2) Cl

3) Br

4) I

30 / 50

If 98 g of H₂SO₄ is completely ionized in 1 L of water, what is the normality of the solution?

1) 0.5 N

2) 0.1 N

3) 1 N

4) 2 N

31 / 50

The working principle of a potentiometer is based on:

1) (a) Ohm’s law

2) (b) Nernst equation

3) (c) Beer-Lambert law

4) (d) Hess’s law

32 / 50

The ideal precipitate in gravimetric analysis should be:

1) a) Highly soluble

2) b) Easily filterable

3) c) Colloidal

4) d) Hydrated

33 / 50

The base peak in a mass spectrum represents:

1) a) The most abundant ion

2) b) The heaviest ion

3) c) The molecular ion

4) d) The neutral molecule

34 / 50

Which is the most abundant protein in the human body?

1) a) Hemoglobin

2) b) Collagen

3) c) Myoglobin

4) d) Keratin

35 / 50

The rate constant for a first-order reaction is 0.001 s⁻¹. What is the half-life of the reaction?

1) a) 693 s

2) b) 1000 s

3) c) 500 s

4) d) 10 s

36 / 50

At 700 K, the equilibrium constant for the reaction is 0.50. What is if

1) a) 0.0115

2) b) 0.046

3) c) 0.50

4) d) 1.2

37 / 50

Which of the following is used as a reference electrode in potentiometry?

1) (a) Hydrogen electrode

2) (b) Silver-silver chloride electrode

3) (c) Calomel electrode

4) (d) All of the above

38 / 50

Which factor favors an SN1 reaction over an SN2 reaction?

1) a) High steric hindrance

2) b) Strong nucleophile

3) c) Polar aprotic solvent

4) d) Primary alkyl halide

39 / 50

Which detector in gas chromatography is most sensitive for detecting organic compounds?

1) Flame Ionization Detector (FID)

2) Thermal Conductivity Detector (TCD)

3) Electron Capture Detector (ECD)

4) UV-Vis Spectrophotometer

40 / 50

Which of the following is an example of a precipitating agent in gravimetric analysis

1) Hydrochloric acid

2) Ammonium sulfate

3) Sodium chloride

4) Ethanol

41 / 50

The solubility product () of at 25°C is . Calculate its solubility in mol/L.

1) a) 1.05×10−5

2) b) 2.3×10−6

3) c) 3.4×10−7

4) d) 8.9×10−4

42 / 50

Which indicator would be most suitable for the titration of a strong acid with a strong base

1) Phenolphthalein (pH range: 8.2 - 10.0)

2) Methyl orange (pH range: 3.1 - 4.4)

3) Bromothymol blue (pH range: 6.0 - 7.6)

4) none

43 / 50

In the redox titration to determine the concentration of I2 with known solution of Na2S2O3, the end point of the titration is

1) blue to pink

2) blue to colorless

3) pink to colorless

4) pink to blue

44 / 50

The color change in a permanganate redox titration is due to:

1) a) Change in pH

2) b) Formation of MnO₄²⁻

3) c) Reduction of MnO₄⁻ to Mn²⁺

4) d) Precipitation of MnO₂

45 / 50

Karl Fischer titration is used to determine:

1) a) Purity of metals

2) b) Water content in samples

3) c) Alcohol percentage

4) d) Molecular weight

46 / 50

The Fajan’s rule predicts the extent of

1) Covalent character in an ionic bond

2) Ionic character in a covalent bond

3) Metallic character in an element

4) Hydrogen bonding strength

47 / 50

In the equilibrium $C a C O_{3} (s) ⇌ C a O (s) + C O_{2} (g)$ , if the pressure is decreased, what happens to the equilibrium?

1) Shifts to the left

2) Shifts to the right

3) No change, as there are only solids present

4) 𝐾 increases

48 / 50

The half-life of Uranium-238 is 4.5 × 10⁹ years. How much of a 10 g sample will remain after 9 × 10⁹ years?

1) a) 2.5 g

2) b) 5 g

3) c) 1.25 g

4) d) 0.5 g

49 / 50

The indicator used in EDTA titration is:

1) a) Phenolphthalein

2) b) Methyl orange

3) c) Eriochrome Black T

4) d) Starch

50 / 50

In Atomic Absorption Spectroscopy (AAS), the source of radiation is:

1) a) Tungsten lamp

2) b) Hollow cathode lamp

3) c) Monochromator

4) d) Laser

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The average score is 54%