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Determination of PH of soil

TITLE -Determination of PH of soil

DEFINITION - PH is defined a minus the decimal logarithmic of the hydrogen ion activity is a solution by virtue of its logarithmic nature. 
PH is dimensions less quantity. 

EQUIPMENTS FOR SOIL PH- 
PH meter -  It consist of two electrodes. 
A)  - glass electrodes  and
B)  - calomel electrodes (reference      electrodes) 

REAGENTS - 
1) Standard buffer solutions PH 4.00-
Prepare stock solutions of 0.3m potassium hydrogen phthalate by dissolving 15.3gm of the analytical grade salt in about 225ml of hot water. cooling the solution and diluting at 250ml. Add Drop of **** to discharge growth  of micro organisms. For standard buffer pH 4.0 mix 100ml of the stock solutions with 500ml water.  Prepare the fresh solutions every week

2) Standard buffer solutions PH 9.2-
Dissolve 3.81gm sodium tetraborate(AR) in water and dilute to 1000ml. 

3) 1 N potassium chloride solutions (AR) -
Dissolve 74.56gm of kcl in water and make up volume to 1000ml. 

APPARATUS -Electrometric PH meter with glass and  calomel electrodes. 

PROCEDURE -
  • Take  20gm of soil sample in a beaker. 
  • Add 50 my distill water. 
  • Stir for 15 minutes. 
  • Take reading. 
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