Flashcards in Lab Exercise 1 to 6 Deck (34):
What instrument was used to measure turbidity, in the experiment?`(be specific)
Lovibond Turbidity Meter
What unit is used to measure the turbidity, in the experiment?
Nephelometric Turbidity Unit
If ambient temperature of the calibration does not deviate by less than +- 3 degrees Celsius from the current ambient temperature, the measurements are accepted by the unit.
In the turbidity meter, what does it mean when you get a "E01" message?
light absorption too great. Reason may be due to dirty optics
In the turbidity meter, what does it mean when you get a "+Err" message? What must you do?
measuring range exceeded; calibrate it to the next turbidity standard
In the turbidity meter, what does it mean when you get a "-Err" message?
result below the lowest limit of the measuring range
instrument used in the experiment for pH determination
Cyberscan 1100 pH meter
Which display in the meter shows current pH reading and temperature?
D. there is only one display
Be sure to remove electrode soaker bottle or protective rubber cap on the electrode before measurement.
pH electrode is not affected by temperature.
To limit loss of accuracy during calibration, make the temperature of the pH buffer calibrating solution and the sample solution different.
same pa rin
Which is false?
A.Turbidity is the amount of particulate matter that is suspended in water.
B.Turbidity measures the clumping effect that suspended solids have on light.
What is the capacity of water to neutralize a strong base?
When mineral acids are present in water, the water is still safe to drink. T/F
Mineral acidity = 0 if pOH of sample is greater than 4.5
Carbonic acid causes the __ acidity
A. methyl orange
The ff may cause alkalinity of water except
Bitter taste of alkaline water has a negative health impact.
no health risk
Which is not used in acidity determination?
A.methyl orange indicator
B.standard NaOH solution (0.02 N)
Sequence their use in acidity det
A.standard NaOH solution (0.02 N)
C.methyl orange indicator
end point color for acidity det
Which is false?
A.There is no standard value for acidity because there is no direct effect on health.
B.Hypochlorous acid is an effective disinfectant only for pH > 8
C.Temporary hardness can be removed by boiling
Hindi siya effective sa pH > 8
most common source of water contamination by mineral acids
usually from acid mine drainage (when mineral deposits that contain sulfides are mined)
true about Zero Phenolphthalein Alkalinity (PA)
A. ↓Carbon and OH-
B. no bicarbonate
C. acidity is low
bicarbonate predominates here
true about Phenolphthalein Alkalinity (PA)
A. If PA is greater than ½ of total alkalinity: carbonate ions predominate
B. If PA is less than ½ of total alkalinity: OH- ions predominate
permanent hardness cannot be removed by:
A.addition of washing soda (sodium carbonate)
D.use of polyphosphate water softeners
Alkalinity Determination: If sample does not turn pink, how are the reagents arranged?
C.0.02N H2SO4 titrant
identify end point color in alkalinity det
Methyl orange is
__in alkaline solution, __ in neutral, and __ in acid.
hardness det: how are reagents arranged?
A.Eriochrome Black T indicator
C.Ammonia buffer solution
identify end point color in hardness det (assume freshly prepared reagent)
"Duration of titration should not exceed 5 minutes measured from the time the buffer is added."
In what expt is this applicable?
A. acidity det
B. alkalinity det
C. hardness det
D. calcium det
Calcium det: how are reagents arranged?