[raymanh]

Hi,

I'm doing this for my Geography degree so I have no idea if this should be under High school or Undergraduate sub-forums. Apologies if I got it wrong.

A few questions:

1.

I'm mixing in ammonium salts with water to make an ammonia solution for use as a nutrient. How do I transform grams of the salt into ammonia-N concentration?

Say I have 5 litres of water and add 10g of NH4Cl salt.

Would my concentration (NH4-N, grams/L) be (10g * (14/53.49))/5 liters.
(14 is the molecular weight of N, and 53.49 is molecular weight of NH4Cl)

2.

Another thing is the difference between concentration in 'NH4' and concentration in 'NH4-N'. I assume the above will give me the concentration in NH4-N as it uses the molecular weight of N, but what does '-N' refer to, and how do I convert between 'NH4-N' and NH4?

3.
Where can I find out what the maximum saturation is for NH4Cl in water? I will also be dissolving other salts in the same water (sodium nitrate and potassium phosphate). If the solution is saturated in one, will I be able to dissolve less of the other two? I.e. say I dissolve all three salts in one 5L container until it is saturated with all three, and then compare it to if I dissolved each salt in it's own 5L container... will the concentrations in respective containers be the same?

Thanks in advance.

[raymanh]

Can anyone help?

[Arkcon]

I'm sorry you haven't had better help yet.  However, all I can say is, "I guess your math is correct." 

I can't find any reference for what the N-P-K nomenclature commonly used in fertilizers really means.  It makes sense that the N is percentage of nitrogen, and you're converting correctly, but I can't be more definitive than that.

[Corribus]

NPK = nitrogen, phosphorous, potassium