Neutralizing HNO2 and HNO3 with caustic

[corrjay]

Quick question, this may have been posted before, but if I had 12,000 ppm or dissolved nitrate and 300-9000 ppm of dissolved nitrite do you know how much NaOH I would need to try and neutralize it since i have a pH of ~1.9?

Is it almost a 1:1 ratio: i.e. with 5000 ppm nitrite I would need 5000 ppm sodium hydroxide?

 

[orenda1168]

This is high school chemistry, which if you are in fact a chemical engineer, or at least a chemist, you should not be asking the question about!

If you wish to simply neutralize the mix, take a reprsentative sample and titrate it with a sodium hydroxide solution to a pH 7. Calculate the amount of sodium hydroxide from the titration required to neutralize the solution.

Orenda

 

[m777182]

HNO2 and HNO3 are both very strong monovalent acids. If you neutralize them with NaOH there will be no buffer action,the pH at equilibrium =7.You can simply calculate mols of both acids and add the same amount (in mols!) of NaOH.
m777182

 

[nbucska]

Isn't CaO cheaper?


Plesae read FAQ240-1032
My WEB: <

http://geocities.com/nbucska/>

 

[ChemBuddy]

m777182 - you are wrong. While HNO3 is strong (although much weaker than HCl and first step of H2SO4) HNO2 is simply weak acid, with pKa 3.37.

General Chemistry Software
www.pH-meter.info

 

[25362]

To my grasping the answers by orenda1168 and Chembuddy are right. The acidity could be the effect of cations. For example, 0.1 M aqueous solutions of Fe(NO₃)₃ and NaNO₃ at 25 deg C would show pH values of 1.6 and 7.0, respectively. Iron(III) acts as an acid through Fe(H₂O)₆³⁺.

 

[m777182]

Yes, ChemBuddy, I am wrong. HNO2 is not as strong as I had in mind and it will make some buffering. So an titration experiment(s) is(are) needed.
Thanks for correcting me.
m777182