Unit 31Nitrogenous fertilizers Part I

1
Unit 31 Nitrogenous fertilizers Part I

• Calculate the mass of N-P-K in fertilizers.
• Calculate percentage by mass of nutrients in
  fertilizers.
• Manufacturing ammonia, NH3, Haber Process

2
percentage by mass N 20 P2O5 8 K2O 14
Calculate the mass of N, P and K in 750 kg of
fertilizer on left. given N 14, P 31, K
39.1
Ans N 150 kg P 26.2 kg K 87.2 kg
3
2. Calculate percentage by mass of nutrients in
fertilizers.
e.g 31.1 Calculate by mass of N in
(NH4)2SO4 Given N 14, H 1, S 32, O
16 Ans 21.2
e.g 31.2 Calculate by mass of N in 100 g of
fertilizer (which contain 66 g (NH4)2SO4). Given
Molar mass of (NH4)2SO4 132 g mol-1 Ans 14
4
2. Calculate percentage by mass of nutrients in
fertilizers.

• Class works A fertilizer is made from 50 NH4NO3
  , formula mass 80, and 40 of (NH4)2HPO4 ,
  formula mass 132.
• Calculate by mass of N in NH4NO3.
• Calculate by mass of N in (NH4)2HPO4.
• Calculate by mass of N in that fertilizer.
• Ans (a) 35 (b) 21.2 (c) 26