Lab Analysis Flashcards
Turbidity analyses on samples should be measured?
As soon as possible.
Which sample quantity should be collected for a
hardness analysis?
100 mL
Which is the minimum size turbidity sample that
should be collected?
100 mL
Which sample should not be collected in a glass container?
Fluoride
Bacteriological sample storage refrigerator temperatures
should range from ____________.
10 to 50 c
How long can a preserved sample that is to be analyzed
for manganese content be stored?
6 months
Samples to be analyzed for manganese are preserved with?
Nitric Acid
In the total coliform colisure test, if coliforms are present,
the special medium will turn?
Red to purple
What is the chemical formula for ammonia?
NH3
Electrically charged atoms such as Na+ and Cl-
are called?
Ions
How often should a softening treatment plant analyze
for hardness?
Daily
Which test would be used to determine
total alkalinity?
Methyl Orange test
Which method is used to calculate the calcium carbonate
stability of water?
Langelier Index
Who is responsible for sample preservation?
The sampler
If hardness samples need to be stored, which preservative
should be used?
Nitric acid
How long can samples be held for fluoride analysis?
7 days
Which water quality parameter can be properly determined
by collecting a composite sample?
Zinc
Water that is to be analyze for inorganic metals should be
acidified to a pH that is _______.
< 2.0 pH units
Nematodes are?
Roundworms
An actinomycetes bacterial colony on an agar plate
would have a ________.
Dull powdery appearance with fuzzy border.
Which level of Threshold Odor Number (TON) will
result in customer complaints?
5 (TON)
Suspended solids that are referred to as settleable solids
will settle unaided to the bottom of a sedimentation
basin within?
4 hours
What would be considered very hard water measure in
mg/L as CaCO3 for the Sawyer, Briggs, or
Ficke classification?
> 300 mg/L
Water that is too soft will cause?
Soap scum
Why is it important to measure
Total Organic Carbon
(TOC)
TOC correlates with production of disinfection
by-products?
Which element is found in all acids?
Hydrogen
When a base reacts with an oxide of a nonmetal
it will produce _______.
A salt
When anhydrides react with water they produce?
Acids and hydroxides
Oxides of nonmetals in water will _______.
cause acidity.
What is the formula for the
Langelier Index?
Ll = pH - pHs
Giardia lamblia species are?
Protozoans
The specific gravity of water is based on using
a temperature of _______.
40 c
Jar testing procedures are applicable to ________.
conventional treatment.
The incubation time for the membrane filter method is?
24 hours
Which type of glassware is used in dispensing solutions
during titrations?
Burette
Samples confirmed in the presence-absence test
must also be tested for?
Escherichia Coli
(e-coli)
Which should the heterotrophic plate count value be in
water that has been properly treated?
< 500 colonies per mL
Why should a Jar test procedure be done as quickly
as possible after collecting the raw water sample?
Changes in temperature will
significantly affect results.
Which is the preferred method of hardness analysis?
Titration with
ethylenediaminetetraacetic
acid
Which method is used for Fluoride analysis?
SPADNS
When EDTA is added to a sample being tested for
hardness, the end point causes the dye in the
sample to change to _______.
blue