If the contents of exchangeable ions (cmol kg⁻¹) determined in soil are Na⁺ = 5, K⁺ = 5, Ca²⁺ = 10, Mg²⁺ = 2, H⁺ = 1, Al³⁺ = 1, Cl⁻ = 1.6 and HCO₃⁻ = 0.4, the CEC of soil is

✅ Explanation:
Cation Exchange Capacity (CEC) is the total capacity of a soil to hold exchangeable cations. It's a crucial soil property influencing nutrient availability and soil fertility. CEC is calculated by summing the charge equivalents of all the exchangeable cations.

• Here's the breakdown:

✏️Monovalent cations (charge +1):
-Na⁺ = 5 cmol kg⁻¹
-K⁺ = 5 cmol kg⁻¹
-H⁺ = 1 cmol kg⁻¹
-Total charge from monovalent cations = 5 + 5 + 1 = 11 cmol kg⁻¹

✏️Divalent cations (charge +2):
-Ca²⁺ = 10 cmol kg⁻¹
-Mg²⁺ = 2 cmol kg⁻¹
-Total charge from divalent cations = (10 x 2) + (2 x 2) = 20 + 4 = 24 cmol kg⁻¹

✏️Trivalent cations (charge +3):
-Al³⁺ = 1 cmol kg⁻¹
-Total charge from trivalent cations = 1 x 3 = 3 cmol kg⁻¹
-Anions (negative charge) are not included in CEC calculations
-Total CEC = Charge from monovalent cations + Charge from divalent cations + Charge from trivalent cations.
-Total CEC = 11 + 24 + 3 = 24 cmol (P⁺) kg⁻¹