Licensure Examination for Chemical Technicians Flashcards
Compiled Past Board Exam Questions October 29, 2021
Benzene and its derivatives undergo substitution reactions instead of addition reactions because
A. the integrity of the benzene ring and the stable pi-bonding pattern remains intact.
B. the hydrogens of benzene are relatively loosely bound.
C. the benzene ring is sterically crowded hence only substitution can occur.
D. the benzene ring is electron rich.
A. the integrity of the benzene ring and the stable pi-bonding pattern remains intact.
Electrophiles are
A. electron deficient species
B. electron rich species
C. electrically neutral species
D. positively charge ion
A. electron deficient species
SN2 means
A. two step nucleophilic substitution mechanism involving both alkyl halide and nucleophile.
B. one step nucleophilic substitution mechanism involving both alkyl halide and nucleophile.
C. two step nucleophilic substitution mechanism involving only the alkyl halide.
D. one step nucleophilic substitution mechanism involving only the nucleophile.
B. one step nucleophilic substitution mechanism involving both alkyl halide and nucleophile.
In the decomposition and dissolution of solids during sample preparation, which of the following is expensive and often the last resort?
A. Acid treatment using oxidation
B. Fusion technique
C. dissolution using ultrasound & appropriate solvent
D. Simple dissolution
B. Fusion technique
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 ____________.
A. matrix
B. analyte
C. weight
D. ash
B. analyte
Glass container is not suitable for
A. inorganic trace analyses
B. oil and grease determination
C. microbiological analyses
D. all of the above
A. inorganic trace analyses
Which of the following is a primary standard for use in standardizing bases?
A. Ammonium hydroxide
B. Sulfuric acid
C. Acetic acid
D. Potassium hydrogen phthalate
D. Potassium hydrogen phthalate
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.
A. 10.10%
B. 9.25%
C. 12.2%
D. 5.10%
D. 5.10%
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?
A. 50 ppm Zinc, 32 ppm Cd, 25 ppm Pb
B. 100 ppm Zinc, 75 ppm Cd, 50 ppm Pb
C. 5 ppm Zinc, 75 ppm Cd, 50 ppm Pb
D. 100 ppm Zinc, 25 ppm Cd, 25 ppm Pb
B. 100 ppm Zinc, 75 ppm Cd, 50 ppm Pb
The HPLC column type in which molecules are separated according to size.
A. ion exchange
B. size exclusion
C. normal phase
D. reverse phase
B. size exclusion
During ignition for ashing, muffle furnaces that go up to 1100°C are used primarily for this and ________ is needed to contain the sample.
A. porcelain crucible
B. evaporating dish
C. beaker
D. all of the above
A. porcelain crucible
A graphical representation of measuring signal as a function of quantity of analyte.
A. Calibration Curve
B. Quality Control Chart
C. Absorbance Chart
D. None of the above
A. Calibration Curve
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.
A. sample dilution
B. using an alternative wavelength having a lower absorptivity
C. reducing the path length by rotating the burner hand
D. All of the above
D. All of the above
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:
A. take the average of multiple measurements using the graduated cylinder.
B. measure the liquid using a 25 mL graduated cylinder instead.
C. estimate the measurement obtained from the graduated cylinder to an additional significant figure.
D. measure the liquid using a 10 mL graduated pipette instead.
D. measure the liquid using a 10 mL graduated pipette instead.
A buffer solution may be a mixture of
A. a weak acid and its salt
B. a weak base and its salt
C. an excess of a weak acid with a strong base
D. all of the above
D. all of the above
Which statement is true?
A. The value of the equilibrium constant increases with the addition of a catalyst.
B. A catalyst speeds up both the forward and reverse reaction rates.
C. The greater the activation energy, the faster the rate of reaction.
D. A catalyst increases the rate of reaction by decreasing the number of collisions.
B. A catalyst speeds up both the forward and reverse reaction rates.
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 25.0°C?
A. 0.191 L
B. 2.28 L
C. 19.1 L
D. 22.8 L
B. 2.28 L
Molecular oxygen is highly soluble in the blood because
A. the hemoglobin molecule can bind up to four oxygen molecules.
B. the solubility of oxygen is increased by the higher temperature of the body.
C. pressure is increased inside the body.
D. pressure inside the body is different outside of it.
A. the hemoglobin molecule can bind up to four oxygen molecules.
When water is heated in a beaker, bubbles of air form on the side of the glass before the water boils. This shows that
A. the solubility of gases in water decreases with increasing temperature.
B. the solubility of gases in water increases with increasing temperature .
C. the solubility of gases in water decreases with decreasing temperature.
D. the solubility of gases in water increases with decreasing temperature.
A. the solubility of gases in water decreases with increasing temperature.
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.
A. 0.0524
B. 0.0552
C. 0.0465
D. 0.00052
A. 0.0524
Method of passing the sample through a metal or plastic mesh of a uniform cross-sectional area to separate particles into uniform sizes.
A. sieving
B. pulverizing
C. macerating
D. milling
A. sieving
In handling acid wastes, what type of protective gloves should be used?
A. Cloth gloves
B. Surgical gloves
C. Rubber gloves
D. Disposal plastic gloves
C. Rubber gloves
What type of container must be used for acid or alkali wastes?
A. Polyethylene Drums
B. Metal Drums
C. Fiber Drums
D. Cloth Container
A. Polyethylene Drums
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.
A. Composting
B. Recycling
C. Bioremediation
D. Reducing
A. Composting
A series of reference standards solutions that have known and accurate pH values at different temperatures used for pH meter calibration.
A. Buffer Solutions
B. QC Solutions
C. pH Solutions
D. None of the above
A. Buffer Solutions
Law that states the linear relationship between absorbance and concentration of an absorbing species
A. Beer-Lambert’s Law
B. Charles’ Law
C. Boyle’s Law
D. Avogadro’s Law
A. Beer-Lambert’s Law
Type of quality-control sample used to evaluate the effects of sample matrices on the performance of an analytical method
A. Matrix Duplicate
B. Matrix Spike
C. Method Blank
D. Reagent Blank
B. Matrix Spike
Component of error which, in the course of a number of analyses of the same measurand, remains constant or varies in a predictable way.
A. Random Error
B. Analyst’s Error
C. Systematic Error
D. Uncertainty
C. Systematic Error
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
A. 50.45 mL
B. 50.27 mL
C. 50.37 mL
D. 50.17 mL
B. 50.27 mL
It is a pure dry solid substance of known chemical composition used in the direct standardization of solution.
A. primary standard
B. secondary standard
C. analytical standard
D. indicator
A. primary standard
It is the closeness of the agreement between the result of a measured value and a true value.
A. Accuracy
B. Precision
C. Mean
D. Error
A. Accuracy
Sample preparation technique used prior to instrumental analysis of metals.
A. acid digestion
B. liquid-liquid extraction
C. sieving
D. clean-up
A. acid digestion
Which of the following chemicals may be used to neutralize waste containing caustic soda?
A. Potassium Hydroxide
B. Ammonia
C. Hydrochloric Acid
D. Buffer 10 Solution
C. Hydrochloric Acid
Which of the following are possible routes of exposure of the hazardous effect of waste?
A. Inhalation
B. Dermal
C. Ingestion
D. All of the above
D. All of the above
According to Revised DAO 04-36, the appropriate waste labels shall include:
A. Volume of Waste
B. Generator ID Number
C. Container Material
D. All of the above
D. All of the above
Sampling type that eliminates questions of bias in selection ___________.
A. composite
B. stratified
C. systematic
D. random
D. random
Reliability of the results decreases with a decrease in the level or concentration of the:
A. matrix
B. analyte
C. reactant
D. product
B. analyte
Properties of nitric acid making it the preferred acid for digesting samples for the analysis of metals.
A. acts as a strong acid
B. as an oxidizing agent
C. does not form insoluble compounds with metals/nonmetals
D. All of the above
D. All of the above
Possible sources of contamination during sample preparation include:
A. Reagents (tracers)
B. Glassware/equipment
C. Cross-contamination between high- and low-activity samples
D. All of the above
D. All of the above
The size of the sample taken for analysis depends on the concentration of the
A. analyte
B. equipment to be used
C. specific tests
D. all of the above
D. all of the above
Locating the adulterated portion of the lot for sampling is an example of
A. random sampling
B. selective sampling
C. composite sampling
D. stratified sampling
B. selective sampling
Quantitative chemical analysis of weighing a sample, usually of a separated and dried precipitate.
A. Titrimetric analysis
B. Volumetric analysis
C. Gravimetric analysis
D. Elemental analysis
C. Gravimetric analysis
The substance which does the dissolving and must be greater than 50% of the solution.
A. solvent
B. solute
C. mixture
D. solution
A. solvent
Requirements of a primary standard.
A. High Purity, 99.9% or better
B. Stability of hydrate water
C. Absence of hydrate water
D. All of the above
D. All of the above