Fundamentals of Soil Science (1+1)

Exercise 9: Preparation of HCl extract

Exercise : Preperation of HCl extract

Material required
Equipment and glassware

• Conical fkask (500ml)
• Glass funnel
• Hot plate, Buchner funnel
• Volumetric flask (500ml)
• Whatman No. 50

Reagents:

• HCl

Procedure

• Place a 20 g of dry soil in a 500 ml conical flask. Add 200 ml of hydrochloric acid
• Place a funnel in the mouth of flask and boil gently for one hour on a sand bath or hot plate. Filter through Whatman No.50 filter paper fitted in a Buchner funnel.
• Wash the residue with hot water containing 50 ml of HCl per litre. The washing should be continued untill 500 ml of the extract is obtained .
• Transfer the filterate to a 500 measuring flask. Cool and make up the volume and call it solution A. Use a suitable aliquot for the determination of potash and other constituent.