In determination of chlorides using argentometric titration, what indicator shall be used
potassium chromate
- In sample acceptance, which of the following shall be checked?
a. sample density
b. sample integrity
c. amount of sample
d. both b and c
b. sample integrity
c. amount of sample
Light sensitive samples should be collected in a/an __________ container.
a. polyethylene bottle container
b. polypropylene container
c. amber bottle container
d. volumetric flask
amber bottle container
. A solution consisting of petroleum ether, n-hexane and ethyl acetate is subjected to
fractional distillation. What compound will be recovered first given the following boiling
points? Dichloromethane = 39.6°C, n-hexane = 68°C, Xylene = 140°C.
Dichloromethane (tempt)
The dilution of concentrated acid is an exothermic process. It is best to:
a. place the flask in a hot water bath.
b. add ice cold water instead of room temperature water.
c. place the flask in a cold water bath.
d. place the flask in a freezer with a temperature of -20ºC
place the flask in a cold water bath.
It is a pure dry solid substance of known chemical composition used in the direct
standardization of solution.
primary standard
aample preparation technique used prior to instrumental analysis of metals.
a. acid digestion
b. liquid-liquid extraction
c. sieving
d. clean-up
acid digestion
Organic compounds in aqueous sample A will be extracted using liquid-liquid extraction. Which of the following is the most appropriate solvent to use?
a. methanol
b. water
c. hexane
d. hydrochloric acid solution
hexane non polar
Sample preparation method in which electromechanically driven rod or vibrating base is
used to break particles down mechanically into smaller units; can be performed in wet or dry
state
pulverized
Which procedure for dispensing a liquid with a volumetric pipet is correct?
A. Draw the liquid up to the line on the pipet using a Piped bulb. Squeeze the bulb to force all the liquid in the pipet into the receiving container.
B. Introduce the liquid into the top end of the pipet until it is filled to the line. Allow the liquid to drain into the desired container. Blow on the pipet to release the last drop.
C. Draw the liquid above the line on the pipet using a pipet bulb. With a finger on the top of the pipet allow the curve
of the meniscus to drop to the line. Place the tip of the pipet against the side of the receiving container and allow
the liquid to drain.
D. Draw the liquid above the line on the pipet by sucking on the open end of the pipet. Place thumb on the top of the
pipet and allow the curve of the meniscus to drop to the line. Allow the liquid to drain into the receiving container
pipet against its side.
C. Draw the liquid above the line on the pipet using a pipet bulb. With a finger on the top of the pipet allow the curve
of the meniscus to drop to the line. Place the tip of the pipet against the side of the receiving container and allow
the liquid to drain.
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
Gravimetric analysis
HCl cannot be considered to be a primary standard because of its gaseous form at room temperature, but its solutions
may be standardized against anhydrous ______.
A. NaSO4
B. NaHCO3
C. Na2CO3
D. All of the above
Na2CO3
These are organic chemicals that are resistant to environmental degradation through chemical, biological, and
photolytic processes.
A. Persistent Organic Chemicals (POPs)
Choose the formula to be used when you have to prepare a 0.3 N solution of NaOH form 5 N NaOH.
A. N1V1=N2V2
B. PV=nRT
C. M=moles/L
D. P1V1=P2V2
N1V1=N2V2
Systematic errors lead to a lack of
a. accuracy in the measurement.
c. precision in the measurement.
b. significant digits in the measurement. d. gradation of the measuring instrument.
accuracy in the measurement.
145.What test is used to determine whether a suspected outlier in a series of determinations can
be rejected or included in the determination of the mean
Q test
Which of the following types of errors can be traced to a defect in the measuring
instrument?
a.Systematic c. Gross
b.Random d.Proportional
a.Systematic
- A characteristic of random errrors is that.
a. they are caused by poorly calibrated apparatus.
b. the error is the same for any measurement taken at random.
c. their effect is decreased by calculating the mean of replicate measurements.
d. their effect is reduced by doing a blank analysis.
their effect is decreased by calculating the mean of replicate measurements.
All of the following are measures of precision except:
a. Standard deviation c. Relative range
b. Relative error c. Relative range
Relative error
Detects contamination from reagents, sample handling, and the entire measurement process
a. method blank c. calibration blank
b. solvent blank d. matched-matrix blank
method blank
Series of analytical measurements used to assess the quality of the analytical data
a. Quality Assurance c. Analytical run
b. Quality Control d. Fortification
Quality Control
- A series of reference standards solutions that have known and accurate pH values at
different temperatures used for pH meter calibration.
a. Buffer Solutions c. pH solutions
b. QC Solutions d. None of the given choices
Buffer Solutions
Which of the following shall not be followed when boiling a solution in a hot plate?
a. Make sure that the glass ware being used is heat resistant
b. Inspect the glass ware for cracks before putting it in the hot plate.
c. Add boiling stones to facilitate boiling.
d. When removing the heated material, use polyethylene gloves to protect your hand from
heat.
When removing the heated material, use polyethylene gloves to protect your hand from
heat.
Which of the following does not require a minimum of annual third party calibration?
a. analytical balance c. autoclave
b. drying oven d. sets of weights
sets of weights
