Chemistry Forum

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

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.

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).

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.