Mix to obtain fertilizer

Chemistry and homework help forum.

Organic Chemistry, Analytical Chemistry, Biochemistry, Physical Chemistry, Computational Chemistry, Theoretical Chemistry, High School Chemistry, Colledge Chemistry and University Chemistry Forum.

Share your chemistry ideas, discuss chemical problems, ask for help with scientific chemistry questions, inspire others by your chemistry vision!

Please feel free to start a scientific chemistry discussion here!

Discuss chemistry homework problems with experts!

Ask for help with chemical questions and help others with your chemistry knowledge!

Moderators: Xen, expert, ChenBeier

Post Reply
BabaVOss
Newbie
Newbie
Posts: 2
Joined: Mon Aug 21, 2023 4:59 pm

Mix to obtain fertilizer

Post by BabaVOss »

Hi everyone. I'm new here.
I have some compounds in the laboratory and I would like to combine them to make a soil fertilizer based on nitrogen, phosphorus, potassium and calcium.

I'm having trouble balancing the equations and knowing:
1- How much of each reagent to use to obtain the proportions I want?
2- Is there any risk mixing any of these compounds?

I looked for some app or tool that made the balances and measurements but I didn't find it. The dilution will be done in water.

This is the list of compounds I have:

Calcium hydroxide Ca(OH)₂
Potassium hydroxide KOH
Sodium hydroxide NaOH
Potassium carbonate K2CO3
Calcium carbonate CaCO₃
Dibasic Sodium Phosphate Na2HPO4
Bibasic Calcium Phosphate CaHPO4
Monobasic Potassium Phosphate KH2PO4

I would like to make fertilizers with different proportions of the elements for different plant species.

Desired proportions:
N : P : K : Ca
8:8:8:3
10:10:10:5
4:14:8:4


Thankyou so much
User avatar
ChenBeier
Distinguished Member
Distinguished Member
Posts: 1565
Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

Re: Mix to obtain fertilizer

Post by ChenBeier »

Mixing is no risk. But your ratios are based on what, mass, mole percentage?
Also the hydroxide, like NaOH make no sense. For Nitrogen you dont have a compound in your list.
BabaVOss
Newbie
Newbie
Posts: 2
Joined: Mon Aug 21, 2023 4:59 pm

Re: Mix to obtain fertilizer

Post by BabaVOss »

Thnks for the answer.
True, I forgot to mention that it would be based on the mass of these elements.

As for NaOH, I ended up making a mess because of the letter "N". The nitrogen source will be through the use of Urea (CH₄N₂O).
User avatar
ChenBeier
Distinguished Member
Distinguished Member
Posts: 1565
Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

Re: Mix to obtain fertilizer

Post by ChenBeier »

First calculate the ratio of each compound.
Urea CH4N2O contain 2 N , means the mass of 1 mol = 60 g correspond to 28 g N
Calcium hydroxide Ca(OH)₂ = 74 g to 40 g
Potassium hydroxide KOH = 56 g to 39 g
Sodium hydroxide NaOH = 40 g
Potassium carbonate K2CO3 = 138 g to 78 g
Calcium carbonate CaCO₃ = 100 g to 40 g
Dibasic Sodium Phosphate Na2HPO4 142 g to 31 g
Bibasic Calcium Phosphate CaHPO4 136 g to 40 g Ca and 31 g P
Monobasic Potassium Phosphate KH2PO4 136 g to 39 g K and 31 g P

8 g N = 28/60 = 8/x x = 17,14 g Urea
8 g P =31/142 = 8/x x = 36,65 g Na2HPO4
8 g K =78/138 = 8/x x = 14,15 g K2CO3
3 g Ca = 40/100 = 3/x x = 7,5 g CaCO3

Other mixtures calculate by yourself.

Note: using CaHPO4 or KH2PO4 will increase Ca and P or K and P in same time.
Post Reply