This procedure is determines of pH value of liquids.
APPARATUS
1. pH meter with the combined electrode.
The front control panel of the pH meter comprises of the following functions:
1) Digital display indicator.
2) Selector switch.
3) Temperature compensate between 0ºC & 100ºC of the solution.
4) Calibrator.
5) Slope.
The rear control is comprised of ïƒ
a). Combined electrode input.
b). On-Off switch.
c). The Main fuse.
d). Power cable.
e). Beaker (100 ml)
f). Thermometer
PROCEDURE
a). Standardize the pH meter with different standard buffer solutions by using ‘calibrator’ and ‘slope’knobs.
b). To check the pH of the liquid sample, take the sample in a clean beaker check the temperature of the sample, and set the temperature compensation knob to this value
c). Clean the electrode with distilled water and dry it by means of tissue paper.
d). Dip the combined electrode inside the sample to a depth of about 1 inch and turn the selector switch from stand by’ to ‘pH’ position. The reading shown on the digital display indicator is the pH value of the sample.
e). Put back the selector switch to stand by position, remove the electrode, wash it with distilled water and wipe with tissue paper. When not in use keep it dipped in a beaker containing distilled water.
>Methods for determination of pH of the water