2.2.1. Analysis
1. Prepare a solution 1.0 N in potassium ion and 0.04 N in bicarbonate
(2 mg CaCO3 equivalent mL−1) by diluting 71.6 g L−1 potassium
chloride (KCl) and 4.044 g L−1 potassium bicarbonate (KHCO3) to
1 L with distilled water.
2. Mix 20.0 g of dry, pulverized soil sample and 40.0mL of the bicarbonate
solution in a 250mL Erlenmeyer flask. Place on an oscillating platform
shaker (200 rpm) for 30 min.
3. Remove the flask fromthe shaker and let it stand for particles to settle.
Filter the supernatant through aWhatman No. 1 filter paper.
4. Pipette 5.00 mL of the filtrate into a 250 mL beaker and dilute to
50.0 mL with distilled water. Titrate to the methyl orange endpoint
with 0.02 N sulfuric acid (H2SO4).