Class Number_______
Agronomy 354 Problem Set 1
Spring 2016
Problem sets are due ca. one week after they are handed out in lecture. To receive full
credit (4 points each), work must be shown as to how the answer was obtained, the
correct answer must be written on the indicated line, the units of the answer must be
indicated and correct, and the assignment must be handed-in by the due date. Check
the course homepage for sample problems and solutions.
1. Aluminum has a normal valence of +3. What is the meq wgt of Al3+ if the atomic
weight is 26.98?
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2. If a soil can hold 440 mg of Mg2+ ions per 100 g, what is the expected CEC of this
soil?
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3. If a soil has a CEC of 17 meq/100 g, how many actual negative charges per 100 g
does this soil have (answer in scientific notation)?
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4. If a soil contains 4.7% organic matter, 14% illite clay, and 17% montmorillinite clay,
what is a reasonable estimate of the CEC of this soil?
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5. If a soil contained 9 meq/100 g of Mg2+, how many ppm (parts per million) would this
equal?
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