Question

3. a) A recommended rate for a certain crop is 160 kg N ha-1. Calculate the weight of Urea needed to supply the desired amount of N on a one ha basis. (1 pt )

b) Calculate the weight of urea to supply the same rate of N to an area of 2000 m2 area. (2 pt)

Answer 1

3. a) molar mass of N = 14.0067g/mol that mean 1 mole of N = 14.0067 gm

molar mass of urea = 60.06g/mol that mean 1 mole of urea = 60.06 gm

for 14.0067 gm N require 60.06 gm urea then 160 kg N require 16060.06/14.0067 = 686.071 kg urea

686.071 kg urea require per hectare

b) 2000m² = 0.2 hectare

686.071 kg urea require per hectare then 0.2 hectare require 686.071 0.2/1 = 137.21 kg

137.21 kg urea require for 2000m² area