Classical pH meter in chemical or clinical laboratory is made with a glass electrode that is selectively sensitive to ______ concentration.
 Na⁺
 K⁺
 H⁺
 OH^-

Calibration should be performed with at least _________buffer(s) that span of range of pH to be measured.
 one
 two
 three
 four

pH meter gives an electrical response proportional to the concentration of hydrogen ion. To convert this response into pH, glass electrode must be calibrated against standard solution of known H+ concentration. Which of the following standard solution(s) is/are likely to be used.
 pH 4.0 buffer
 pH 7.0 buffer
 pH 10 buffer
 All of the above.

After each single measurement, the probe is rinsed with ____________ to remove any trace of the solution being measured.
I. Ionized water
II. Distilled water
III. Deionized water

 I only.
 I and II only.
 II and III only.
 None of the above.

Permissible limit of alkalinity in drinking water is
a : 50mg/l
b : 300mg/l
c : 20-200mg/l
d : 100mg/l

Alkalinity in waste water is useful because it provides buffering to resist changes in pH value.
a : True
b : False

Alkalinity can also be related to hardness because of presence of
a : CaCO₃
b : MgCO₃
c : Na₂CO₃
d : K₂CO₃

Alkalinity is important in aquatic life because
a : It helps water to remain warm
b : It helps water to remain cold
c : It buffers against rapid pH change
d : None of the above

An alkalinity test measures the level of
a : Carbonates only
b : Hydroxides only
c : Bicarbonates, carbonates, and hydroxides
d : None of the above

Higher is the alkalinity in water easier it is for pH change.
a : False
b : True

Excessive alkalinity level in human body can
a : Expel the unwanted pathogens in the bloodstream
b : Cause skin irritations
c : Lead to gastrointestinal issues
d : All of the above