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Quantitative Calcium Carbonate Equivalent Determination in the Field
Author(s) -
Holmgren George G. S.
Publication year - 1973
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1973.03615995003700020038x
Subject(s) - volume (thermodynamics) , analytical chemistry (journal) , calcium carbonate , constant (computer programming) , syringe , chemistry , yield (engineering) , mineralogy , sample (material) , range (aeronautics) , mathematics , chromatography , materials science , thermodynamics , physics , organic chemistry , composite material , psychology , psychiatry , computer science , programming language
A simple volume calcimeter can be constructed from a 50‐cc and a 20‐cc plastic syringe. To operate, a weighted quantity of soil is placed in the large syringe and 5 cc of 10% HCl is drawn into the small syringe. The tips are then joined together through a connecting sleeve and the acid is injected into the soil. The volume of CO 2 produced is measured in either or both syringes, depending on the amount. An array of sample weights to yield 1 cc CO 2 for 1% CaCO 3 equivalent at various temperatures and elevations is provided. This array is approximated by the relation W = (118‐13 h )/T where W = weight of sample in grams, h = elevation in kilometers, and T = temperature, o K. Soluble CO 2 , ranging from 7.3 cc at 5C to 3 cc at 35C, must be added to the observed volume to obtain the true volume of CO 2 released. An alternate procedure using a constant sample weight of 0.33 grams is also described. Directions are given for constructing a simple hand balance to weight this amount in the field, and a nomograph is provided to facilitate calculations. With these procedures, CaCO 3 equivalent can be determined within 1–2% absolute over the range 0–50%. These errors may be reduced at lower CaCO 3 equivalent values by increasing the sample size.