OrgChem Part 3 - 2022 Flashcards
- Solvent extraction is more effective when the extraction is repeated with
A. extra solvent
B. large solvent
C. small solvent
D. no solvent
C. small solvent
- The insoluble impurities during recrystallization are removed by
A. hot gravity filtration
B. vacuum filtration
C. cooling
D. drying
A. hot gravity filtration
- The temperature at which solid and liquid coexist in equilibrium is the
A. melting point of liquid
B. freezing point of liquid
C. freezing point of solid
D. all of the mentioned
B. freezing point of liquid
- During recrystallization, 0.85 g of crude aspirin was dissolved in a suitable solvent and after
filtration and drying, 0.68 g of crystals were recovered. Calculate the % recovery.
A. 20%
B. 50%
C. 65%
D. 80%
D. 80%
- Which of the following is NOT separated using distillation?
A. acetone and water
B. aniline and chloroform
C. impurities in sea water
D. milk and water
D. milk and water
- Steam baths are often used to heat volatile, non-aqueous, flammable solvents because of the
following EXCEPT
A. Can only heat up to 100’C so no overheating occurs in the compounds of the sample
B. Flash fires are unlikely in most solvents
C. Overheating is possible
D. Provides instant heat
C. Overheating is possible
- What is the advantage of steam distillation?
A. Reduces decomposition of temperature-sensitive compounds
B. Reduces decomposition of inorganic compounds
C. Increases the decomposition of temperature-sensitive compounds
D. Increases the decomposition of inorganic compounds
A. Reduces decomposition of temperature-sensitive compounds
- Fractional distillation is a process of separation of which of the following?
A. two immiscible liquids
B. one miscible and one immiscible liquid
C. two miscible liquids
D. none of the above
C. two miscible liquids
- The beads in a fractional column are for
A. vapors to condense
B. vapors to evaporate
C. vapors to generate
D. all of the mentioned
A. vapors to condense
- Which of the following is NOT true about steam distillation?
A. very long extraction times
B. very short extraction times
C. high energy consumption
D. no need for subsequent separation steps
B. very short extraction times
- Which of the following is the correct way to determine the boiling point of an unknown
compound?
A. Heating a compound to boiling and measuring the temperature of the hot plate.
B. Heating a compound to near boiling and placing the thermometer in the liquid.
C. Boiling a compound and placing the thermometer in the refluxing vapor.
D. Boiling a compound and placing the thermometer in the boiling liquid.
C. Boiling a compound and placing the thermometer in the refluxing vapor.
- Karl Fischer titration, which determines trace amounts of water in a sample, uses which
electrochemical method?
A. Potentiometry
B. Coulometry
C. Voltammetry
D. Iodometry
B. Coulometry
- Which of the following is NOT a common method used for purification?
A. Electrolysis
B. Sublimation
C. Crystallization
D. Chromatography
A. Electrolysis
- The principle of TLC is that
A. Different compounds are absorbed on an absorbent to different degrees.
B. Different compounds are absorbed on an absorbent to same degrees.
C. Different compounds are adsorbed on an adsorbent to different degrees.
D. Different compounds are absorbed on an absorbent to same degrees.
C. Different compounds are adsorbed on an adsorbent to different degrees.
- Which of the following statements about visualization during TLC is TRUE?
A. Spots of colorless compounds are invisible to the eyes.
B. Spots can be detected by putting the plate under ultraviolet light.
C. Spots can be detected by placing the plate in a covered jar containing iodine crystals.
D. All Of the above.
D. All Of the above.
- In the decomposition and dissolution of solids during sample preparation, which of the
following is expensive and often the last resort?
A. fusion technique
B. simple dissolution
C. acid treatment using oxidation
D. dissolution using ultrasound and appropriate solvent
A. fusion technique
- Amino acids can be detected by spraying the stationary phase with ninhydrin solution. This
can be done in
A. gas chromatography
B. paper chromatography
C. liquid chromatography
D. column chromatography
B. paper chromatography
- In handling acid wastes, what type of protective gloves should be used?
A. cloth gloves
B. rubber gloves
C. surgical gloves
D. disposal plastic gloves
B. rubber gloves
- The following are the minimum requirements for hazardous waste storage facilities EXCEPT
A. Enclosed and should not be ventilated.
B. Properly secured and not easily accessed by unauthorized persons.
C. Accessible in cases of emergency and for purposes of inspection and monitoring.
D. Equipped with floors that are impermeable to liquids and resistant to attack by chemicals, not
slippery, and constructed to retain spillages.
A. Enclosed and should not be ventilated.
- Which of the following is NOT a good practice in storing chemicals?
A. Store peroxidizable materials away from heat and light.
B. Maintain a clearance Of at least 18 in. from the sprinkler heads to allow proper functioning of
the sprinkler system.
C. Store chemicals directly on the floor.
D. Do not store materials on top of high cabinets where they will be hard to see or reach.
C. Store chemicals directly on the floor.
- A substance is analyzed by paper chromatography, giving the chromatogram shown. What is
the Rf value of the substance represented by the spot at 8.0 cm?
A. 0.80
B. 0.75
C. 0.67
D. 0.60
B. 0.75
- Hazardous waste should be kept separate from other waste because
A. costs are different.
B. different treatments.
C. others can be recycled.
D. all of the above.
D. all of the above.
- Sample preparation technique used prior to instrumental analysis of metals.
A. sieving
B. clean-up
C. acid digestion
D. liquid-liquid extraction
C. acid digestion
- 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. milling
C. pulverizing
D. macerating
A. sieving
- When handling concentrated acids except hydrofluoric acid, which of the following PPE
must be worn?
A. gloves
B. lab gown and safety boots
C. masks with respirators
D. all of the above
D. all of the above
- According to NFPA, what color refers to flammability.
A. blue
B. yellow
C. red
D. white
C. red
- Which of the following should be done when handling flammable and combustible liquids?
A. Keep away from potential ignition sources.
B. Use and store in adequately ventilated areas.
C. Keep container closed except when dispensing.
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. HW class and Number
D. All of the above
D. All of the above
- It is a hazardous waste characteristic which applies to wastes that have the potential to
contaminate groundwater if improperly disposed of. These materials are regulated as hazardous
waste due to their potential to leach out specific toxic substances in a landfill.
A. ignitability
B. reactivity
C. toxicity
D. corrosivity
C. toxicity
- What should you do when a waste container has a minor leak?
A. Patch up the container.
B. Transfer to another container.
C. Call your PCO to report in a regulatory body.
D. Put the container with leak in a bigger container.
B. Transfer to another container.
- An institution that handles chemicals relies on the to make the initial determination of
whether a waste is hazardous and to label the waste accordingly?
A. Laboratory safety manager
B. Department of Environmental and
Natural Resources
C. Principal Investigator
D. Plant Safety Officer
B. Department of Environmental and
Natural Resources
- Organic peroxides are dangerous when
A. heated
B. concentrated
C. you let ether, p-dioxane, THF, among others to vaporize
D. All of the above
D. All of the above
- The following are good sampling practices EXCEPT
A. If possible, mix the material before getting the sample.
B. Take several increments and composite them to form the sample.
C. Sample frequently enough to allow for the identification of process cycles.
D. Collect the sample in a container made of material that will chemically react with the sample.
D. Collect the sample in a container made of material that will chemically react with the sample.
- When using a fume hood, all of the following must be done EXCEPT
A. Making sure that the exhaust is operating.
B. Keeping the hood closed, except during apparatus set-up or when working within the hood.
C. Using the hood as a storage area for volatile chemicals when appropriate storage cabinet is not
available.
D. Removing contaminated items with odors and hazardous materials only after decontamination
or if placed in a closed container to avoid release of contaminants into the air.
C. Using the hood as a storage area for volatile chemicals when appropriate storage cabinet is not
available.
- Which of the following can be disposed down the drain?
A. 1 g/L PCl5
B. 0.1 M H2SO4
C. 200 g/L PCl5
D. None of the above
D. None of the above
- According to the GHS, which of the following is NOT under the pictogram “Gas
Cylinder”?
A. compressed gas
B. dissolved gas
C. liquefied gas
D. explosive gas
D. explosive gas
- When working with chemicals that has splash hazards, what is the most appropriate PPE to
use?
A. Prescription glasses
B. goggles
C. face shield only
D. safety glasses
B. goggles