Identify the correct sequence of Carbon (C) to Nitrogen (N) ratio in…
2020
Identify the correct sequence of Carbon (C) to Nitrogen (N) ratio in decreasing order in organic waste material A. Food waste B. Leaves and foliage C. Paper D. Cow manure
Choose the correct answer from the options given below:
- A.
C, B, D, A
- B.
C, A, D, B
- C.
B, C, D, A
- D.
B, D, C, A
Show answer & explanation
Correct answer: A
Concept
The carbon-to-nitrogen (C:N) ratio measures how many parts of carbon a material carries for each part of nitrogen. Dry, woody, fibrous materials are carbon-rich and have a HIGH C:N ratio; moist, green, protein-rich materials are nitrogen-rich and have a LOW C:N ratio. To arrange materials in decreasing C:N order, list the most carbon-rich (driest/woodiest) first and the most nitrogen-rich (greenest/freshest) last.
Application
Place the four materials by their typical C:N values:
Material | Typical C:N | Nature |
|---|---|---|
Paper | ~150-200 : 1 | Highest - dry cellulose fibre, almost no nitrogen |
Leaves and foliage | ~40-80 : 1 | High - dry brown plant matter, fibrous |
Cow manure | ~20-25 : 1 | Moderate - partly digested, some nitrogen |
Food waste | ~15 : 1 | Lowest - fresh, moist, protein/nitrogen-rich |
Ordering these from highest to lowest C:N gives: Paper, then Leaves and foliage, then Cow manure, then Food waste - that is C, B, D, A.
Cross-check
Sanity check the two close materials at the bottom: cow manure (~20-25:1) still has more carbon per nitrogen than fresh food waste (~15:1), because manure is fibrous part-digested plant material while food scraps are wet and protein-rich. So cow manure (D) correctly comes before food waste (A). The decreasing sequence C, B, D, A holds.