Calcium ammonium nitrate (CAN): approximately what percentage of nitrogen (by mass) does typical commercial CAN fertilizer contain?

Introduction / Context:
Calcium ammonium nitrate (CAN) is a widely used granular nitrogen fertilizer. It is valued for safer handling than pure ammonium nitrate, reduced hygroscopicity, and a mixture of nitrate and ammoniacal nitrogen forms. Farmers and agronomists often need a quick estimate of its nitrogen content for application rate calculations.

Given Data / Assumptions:

• Commercial CAN typically contains roughly 26–27% total nitrogen, often rounded in exam contexts to “about 25%”.
• The product is a mixture of ammonium nitrate with calcium carbonate or dolomite.
• Question asks for an approximate percentage, not an exact plant specification.

Concept / Approach:
Because CAN is diluted ammonium nitrate (by admixture with a calcium source), its nitrogen percentage is lower than that of pure ammonium nitrate (~34% N) and much lower than urea (46% N). Many standard references and competitive exam syllabi treat CAN as “about a quarter nitrogen,” i.e., near 25%.

Step-by-Step Solution:
Recall typical grade labeling: CAN ≈ 26–27% N.The answer choices are coarse; select the nearest standard benchmark.Among 10, 25, 50, and 80, the only realistic approximate value for CAN is 25.

Verification / Alternative check:
Fertilizer handbooks list CAN in the mid-20% nitrogen range, reflecting the stabilizing filler fraction of calcium salts that reduce nitrogen concentration compared with neat ammonium nitrate.

Why Other Options Are Wrong:
10% (too low for CAN), 50% and 80% (far too high, even above urea), and 32% (closer to ammonium nitrate grades rather than CAN) do not match standard CAN specifications.

Common Pitfalls:
Confusing CAN with ammonium nitrate (higher N) or with urea (much higher N). Also, assuming every bag is exactly the same percentage; minor variation exists by manufacturer, but “about 25%” remains the accepted exam value.

Final Answer:
25