Past Board 2021

Question 1

Benzene and its derivatives undergo substitution reactions instead of addition reactions because

Answer 1

the integrity of the benzene ring and the stable pi-bonding pattern remains intact

Question 2

Electrophiles are

Answer 2

electron deficient species

Question 3

Nucleophiles

Answer 3

electron rich species

Question 3

SN2 means

Answer 3

one step nucleophilic substitution mechanism involving both alkyl halide and nucleophile

Question 4

In the decomposition and dissolution of solids during sample preparation, which of the following
is expensive and often the last resort?

Answer 4

Fusion technique

Question 5

It is important to discard containers that are scratched or abraded on their interior surfaces. The
internal surface area of a container, whether used for sample preparation or storage, may cause
loss of

Answer 5

analyte

Question 6

Glass container is not suitable for

Answer 6

inorganic trace analyses

Question 6

Which of the following is a primary standard for use in standardizing bases?

Answer 6

Potassium hydrogen phthalate

Question 7

A student has got three stock standard solutions of 3 different elements, zinc (Zn) 2000 ppm,
cadmium (Cd) 1500 ppm and lead (Pb) 1000 ppm. A student took 10 mL from each solution and
transfers it to 200 mL volumetric flask then completed to total volume with solvent. What is the
final concentration of each element in the diluted mix solution?

Answer 7

100 ppm Zinc, 75 ppm Cd, 50 ppm Pb

Question 7

A solution has been prepared by transferring 60 mL from Ortho-phosphoric acid 85 % (v/v)
H3PO4 and diluting it to 1.0 L, what is the concentration of the new solution.

Answer 7

5.10%

Question 7

The HPLC column type in which molecules are separated according to size.

Answer 7

size exclusion

Question 8

During ignition for ashing, muffle furnaces that go up to 1100oC are used primarily for this and
________ is needed to contain the sample.

Answer 8

porcelain crucible

Question 9

A graphical representation of measuring signal as a function of quantity of analyte.

Answer 9

Calibration curve

Question 10

In AAS method, If the sample concentration is too high to permit accurate analysis in linearity
response range, there are alternatives that may help bring the absorbance into the optimum
working range.

Answer 10

All of the above (sample dilution, using an alternative wavelength having a lower absorptivity, reducing the path length by rotating the burner hand)

Question 11

A student has to measure out 9.40 mL of a liquid and selects a 100 mL graduated cylinder. To
improve the accuracy of the measurement, it would be most effective to:

Answer 11

measure the liquid using a 10 mL graduated pipette instead

Question 11

A buffer solution may be a mixture of

Answer 11

all of the above (weak acid and its salt, a weak base and its salt, an excess of a weak acid with a strong base)

Question 11

What volume is occupied by 4.00 g of carbon dioxide, CO2 (44.0) gas at a pressure of 0.976 atm
and a temperature of 25.00C?

Answer 11

2.28 L

Question 11

Which statement is true?

Answer 11

A catalyst speeds up both the forward and reverse reaction rates

Question 11

Law that states the linear relationship between absorbance and concentration of an absorbing
species

Answer 11

Beer-Lambert’s Law

Question 11

Molecular oxygen is highly soluble in the blood because

Answer 11

the hemoglobin molecule can bind up to four oxygen molecules

Question 12

A series of reference standards solutions that have known and accurate pH values at different
temperatures used for pH meter calibration.

Answer 12

Buffer Solutions

Question 12

Type of quality-control sample used to evaluate the effects of sample matrices on the
performance of an analytical method

Answer 12

Matrix Spike

Question 12

What type of container must be used for acid or alkali wastes?

Answer 12

Polyethylene Drums

Question 12

When water is heated in a beaker, bubbles of air form on the side of the glass before the water
boils. This shows that

Answer 12

the solubility of gases in water decreases with increasing temperature

Question 12

The absorbance of different concentrations of potassium permanganate determined through UV- Vis Spectrophotometer is shown below. Concentration, ppm Average Absorbance 1.11 0.015 22.2 0.236 44.4 0.512 66.6 0.751 88.8 1.062 The Quality Control Sample for this run gave an average absorbance reading of 0.486. The theoretical concentration of the QC sample is 44.4 ppm. Calculate for the error of this QC run.

Answer 12

0.0524

Question 12

Method of passing the sample through a metal or plastic mesh of a uniform cross-sectional area to separate particles into uniform sizes.

Answer 12

sieving

Question 12

A solid waste management practice which refers to the controlled decomposition of organic matter by microorganisms, mainly bacteria and fungi, into a humus-like product.

Answer 12

Composting

Question 12

In handling acid wastes, what type of protective gloves should be used?

Answer 12

Rubber gloves

Question 12

Component of error which, in the course of a number of analyses of the same measurand, remains constant or varies in a predictable way.

Answer 12

Systematic Error

Question 13

Determine the actual volume contained in a 50.0 mL volumetric flask given the following data: Mass of water: 50.1227 g Density of water at 25 ̊ C : 0.99707 g/mL

Answer 13

50.27 mL

Question 13

It is a pure dry solid substance of known chemical composition used in the direct standardization of solution.

Answer 13

primary standard

Question 14

Which of the following chemicals may be used to neutralize waste containing caustic soda?

Answer 14

Hydrochloric Acid

Question 15

Sample preparation technique used prior to instrumental analysis of metals.

Answer 15

acid digestion

Question 15

It is the closeness of the agreement between the result of a measured value and a true value.

Answer 15

Accuracy

Question 15

Which of the following are possible routes of exposure of the hazardous effect of waste?

Answer 15

all of the above (Inhalation, Dermal, Ingestion)

Question 16

According to Revised DAO 04-36, the appropriate waste labels shall include:

Answer 16

All of the above (Volume of Waste, Generator ID Number, Container Material)

Question 16

Sampling type that eliminates questions of bias in selection

Answer 16

random

Question 16

Reliability of the results decreases with a decrease in the level or concentration of the:

Answer 16

analyte

Question 17

Properties of nitric acid making it the preferred acid for digesting samples for the analysis of metals.

Answer 17

All of the above (acts as a strong acid, as an oxidizing agent, does not form insoluble compounds with metals/nonmetals)

Question 18

Possible sources of contamination during sample preparation include:

Answer 18

All of the above (Reagents (tracers), Glassware/equipment, Cross-contamination between high- and low-activity samples)

Question 18

Locating the adulterated portion of the lot for sampling is an example of

Answer 18

selective sampling

Question 18

The size of the sample taken for analysis depends on the concentration of the

Answer 18

All of the above (analyte, equipment to be used, specific tests)

Question 18

Requirements of a primary standard.

Answer 18

All of the above (High Purity, 99.9% or better, Stability in air, Absence of hydrate water)

Question 18

Used for vacuum filtration using filter paper.

Answer 18

Buchner funnel

Question 19

The substance which does the dissolving and must be greater than 50% of the solution.

Answer 19

solvent

Question 19

Quantitative chemical analysis of weighing a sample, usually of a separated and dried precipitate.

Answer 19

Gravimetric analysis

Question 19

A technique for separating mixtures into their components in order to analyze, identify, purify, and/or quantify the mixture or components.

Answer 19

Chromatography

Question 19

Chromatography is used to

Answer 19

All of the above (Separate two or more compounds based on their polarities, Separate two or more compounds based on their masses, Separate two or more compounds based on how strongly they interact with other compounds)

Question 20

In chromatography, ________ is carried out on glass plates or strips of plastic or metal coated on one side with a thin layer of adsorbent.

Answer 20

Thin Layer Chromatography

Question 21

A graph showing the detectors response as a function of elution time : band’s shapes, position, resolution

Answer 21

chromatogram

Question 21

Under the Bronsted concept of acids and bases, an acid is

Answer 21

a proton donor

Question 21

Predict the products of the following acid-base reaction: NH3(aq) + HNO3(aq) →

Answer 21

NH4NO3(aq)

Question 21

Under the Bronsted concept of acids and bases, a base is

Answer 21

a proton acceptor

Question 21

The solution of impure compound and solvent is concentrated to get ____________

Answer 21

Saturated solution

Question 21

Which of the following is not a common method used for purification?

Answer 21

Electrolysis

Question 21

Which of the following is NOT an acid-base conjugate pair?

Answer 21

H2S and OH−

Question 21

Crystal phases can be interconverted by varying ____________

Answer 21

Temperature

Question 21

Insoluble impurities from solution during crystallization are removed by ____________

Answer 21

Filtration

Question 22

Which of the following is not separated through distillation process?

Answer 22

Milk and water

Question 22

Column chromatography is based on the principle of _______________ (this question appeared twice)

Answer 22

Differential adsorption

Question 23

Select the correct statement from the following options.

Answer 23

The greater the polarity of solute, more strongly it will be adsorbed on a polar surface

Question 24

The elution power of a solvent is determined by ____________

Answer 24

All of the mentioned (Its overall polarity, The polarity of the stationary phase, The nature of the sample components)

Question 25

The principle on which thin layer chromatography is based is that the ____________

Answer 25

Different compounds are adsorbed on an adsorbent to different degrees

Question 26

Which type of chromatography is used for the structural analysis?

Answer 26

Paper chromatography

Question 27

Which of the following is not an application of high performance liquid chromatography?

Answer 27

Elimination of undesirable substances from blood

Question 27

Which of the following is the application of ion exchange chromatography?

Answer 27

All of the mentioned (The softening of hard water, The demineralisation of water, The separation and determination of anions)

Question 27

Affinity chromatography is used for the analysis and isolation of ____________

Answer 27

All of the mentioned (Insoluble starch substances, Enzyme tyrosinase, Antibodies bound with a covalently-attached antigen on cellulose column)

Question 28

The quantitative analysis is done using ____________

Answer 28

Gas chromatography

Question 29

The temperature at which solid and liquid coexist in equilibrium is called ____________

Answer 29

Freezing point of liquid

Question 30

The analysis of electromagnetic radiation scattered, absorbed or emitted by the molecule is called

Answer 30

Spectroscopy

Question 31

The different types of energies associated with a molecule are __________

Answer 31

All of the mentioned (Electronic energy, Vibrational energy, Rotational energy)

Question 31

Select the correct statement from the following option.

Answer 31

Spectroscopic methods require less time and less amount of sample than classical methods

Question 32

Which of the following is not in the infrared spectrum?

Answer 32

CH4

Question 33

The components of the mixture in column chromatography are eluted in order of

Answer 33

increasing polarity and increasing distribution ratio.

Question 34

Which equipment must be used in the detection of Pb2+ in blood?

Answer 34

AAS

Question 35

An industrial source of alcohol

Answer 35

Sugar

Question 35

What is the most common isotope of hydrogen?

Answer 35

Protium

Question 36

A 22/24 stopper is used in a volumetric flask. Which of the following is true? (Same concept as this).

Answer 36

The diameter is 22 mm and the height is 24 mm.

Question 36

In the analysis of a mixture by gas chromatography, which of the following gives the best clue as to whether the components can be analysed with any degree of accuracy? (Same concept)

Answer 36

Retention times

Question 37

The determination of the equilibrium constant of a colored species can be done via which technique?

Answer 37

Spectrophotometry

Question 37

This type of glass is commonly used for laboratory glassware.

Answer 37

Borosilicate

Question 38

Why is there a need to separate halogenated waste from non-halogenated waste?

Answer 38

Halogenated waste disposal is more costly

Question 39

Organic peroxides are dangerous when

Answer 39

All of the above (Heated, Concentrated, Let ether, p-dioxane, THF, among others to vaporize)

Question 40

This quality system standard is a general requirement for the competence of testing and calibration laboratories.

Answer 40

ISO/IEC 17025:2005

Question 40

As P increase while T drops, intermolecular forces are evident, what is applicable?

Answer 40

Ideal gas must be replaced by Van der Waals (?)

Question 41

In an ideal gas of volume V and temp T. What happens to T when volume is doubled under constant P?

Answer 41

Doubled

Question 41

Water is a good solvent for benzoic acid recrystallization.what is the correct preparation of benzoic solution for recrystallization.

Answer 41

Add small portions of hot water to benzoic acid while stirring until dissolved

Question 42

If you are going to mass produce vitamin C, which standard should you subscribe in?

Answer 42

GMP or ISO 9000 (or both)

Question 42

What is the name of RA 6969?

Answer 42

The choices were quite confusing. The correct one should be “Toxic Substances and Hazardous and Nuclear Wastes”

Question 42

What type of reactions is hydrogen peroxide to water and oxygen?

Answer 42

Decomposition

Question 42

What compound is possibly shown in an infrared spectrum which has peaks of 3000 cm-1 and 1650 cm-1

Answer 42

Cyclohexene (?)

Question 42

According to NFPA, what color refers to flammability

Answer 42

Red

Question 42

A solution is _______ if more solute can dissolve in it.

Answer 42

unsaturated

Question 43

Solutions of metals and salts are ______

Answer 43

(NA yet)

Question 43

Complete name of the acronym MSDS

Answer 43

Material Safety Data Sheet

Question 44

How many isomers do C5H12 have?

Answer 44

3

Question 44

Which of the ff are limitations of Lambert-Beer's Law?

Answer 44

All of the above (Scattering of light due to particles, Fluorescence of sample, Non-monochromatic radiation)

Question 44

Which of the ff requires the most energy for electronic transition?

Answer 44

Alkanes

Question 44

Which of the following compounds have the same molecular and empirical formula?

Answer 44

(Choices: Different structures of carboxylic acids )

Question 45

The process that combines alcohol and carboxylic acid to form an organic compound and water is called ____

Answer 45

Esterification

Question 45

Which of the following will cause the mass of the metal block to increase?

Answer 45

None of the above (Putting the block in a freezer, Heating the block, Measuring the mass of the block in Jupiter)

Question 45

The process in which the relationship of the analytical response and the concentration of the analyte is established.

Answer 45

Calibration

Question 46

Which of the following is an acid?

Answer 46

Apple juice

Question 46

When proteins are broken down by enzymes, the products are:

Answer 46

amino acids

Question 46

What type of cell converts chemical to electrical energy?

Answer 46

Voltaic or galvanic cells (or both)

Question 46

Which compound will rapidly decolorize bromine in CHCl3

Answer 46

1-hexene

Question 46

The gas-solid chromatography is ____________ chromatography as per basic principle involved

Answer 46

Adsorption

Question 46

Presence of a functional group in a compound can be established by using:

Answer 46

IR Spectroscopy

Question 47

What is the advantage of using ground glass joints when carrying out a chemical reaction?

Answer 47

All of the above (?), (no purities are introduced in the reactions from corks or rubber stopper, all joints are interchangeable and a good fit is assured, glassware apparatus can easily be assembled)

Question 47

Which compounds have both cis and trans isomers possible?

Answer 47

Choices: Different organic compounds were given but you can choose which one is an alkene.

Question 47

125. A compound is known to decompose at its boiling point. Which of the following methods can be used to purify this substance

Answer 47

steam distillation