Humic substance, which is most resistant to microbial attack is:
Humin: Highest in molecular weight, darkest in colour, insoluble in both acid and alkali and most resistant to microbial attack. Polymerized product of a part of the FA and HA fractions.
{(84.04% of 649.95 + 27.92 × 13.13) – 21.11 × ?} = 763.35
2470.03 ÷ 64.98 x 39.9 = ? + 20.32
? = 54.89 × 270.08 ÷ 135.17 + 464.35 ÷ 29.03
1299.99 ÷ 20.21 = ? + 325.985 - (180 ÷ 6 × 24.03)
(899.117 + 1.1121) X 72.731 = ? + 49.95 X 64.78 + 29.50
837.04 × 4.02 + 40.04% of 3049.98 – 3667.82 = ? 2 – 60.87
(5.013 – 30.04) = ? + 11.98% of 4799.98
[(120.96 × 12.09) ÷ ?] ÷ 6 = 19.96% of 55.07
