Sulfuric Acid; Check My Math Please...

[Sean Clark]

I would like someone to double/triple check my math.

I would like to make a 0.02N / 0.01M solution of sulfuric acid.

This is where I am at so far:
Starting with a 98% ACS sulfuric acid concentration with a normality of 36.8, I was going to first make a 1000ml solution at 1N by adding 27.2ml to 972.8ml of RODI water.
I was then going to take that 1N solution and dilute it with 49 parts RODI and 1 part 1N sulfuric acid solution to get a 0.02N solution.
So 20ml of 1N solution to 980ml RODI for 1000ml to make a 0.02N solution.

Am I thinking about this correctly or am I missing something super obvious?

Thanks for any input.

 

[MnFish1]

@Randy Holmes-Farley

The bigger question - 'why'

 

[Sean Clark]

@Randy Holmes-Farley

The bigger question - 'why'

This is for an alkalinity titration reagent.

 

[MnFish1]

This is for an alkalinity titration reagent.

OK. Thanks - I'm not sure many people recommend this - so I was wondering why you thought you needed acid? Most regimen that I have seen rely on Muriatic acid - not sulfuric. Just curious - not debating. Why not just decrease your dose of alkalinity?

 

[Sean Clark]

OK. Thanks - I'm not sure many people recommend this - so I was wondering why you thought you needed acid? Most regimen that I have seen rely on Muriatic acid - not sulfuric. Just curious - not debating. Why not just decrease your dose of alkalinity?

This is not to lower my system's alkalinity. It is for making my own reagent for my KHG alkalinity tester. I am just trying to make my own reagent and see how it works out and if I can save some money by doing so.

 

[MnFish1]

This is not to lower my system's alkalinity. It is for making my own reagent for my KHG alkalinity tester. I am just trying to make my own reagent and see how it works out and if I can save some money by doing so.

working on it - with son - a chemistry major

 

[MnFish1]

This is not to lower my system's alkalinity. It is for making my own reagent for my KHG alkalinity tester. I am just trying to make my own reagent and see how it works out and if I can save some money by doing so.

By .02N / .01M are they trying to say that a .02N solution is the same as a .01M solution? (reply)

 

[Sean Clark]

By .02N / .01M are they trying to say that a .02N solution is the same as a .01M solution? (reply)

That is my understanding yes. . I do know that 1N=.05M so I presume that .02N=.01M. I could be wrong on that though.

 

[MnFish1]

The end comment - why not use molarity throughout

 

[Sean Clark]

The end comment - why not use molarity throughout

Only because the numbers get pretty small. Either way the math should be the same. The 98% sulfuric acid has a molarity of 18.4 just for reference.

 

[Sean Clark]

The N v M shouldn't even matter as far as the quantities are concerned. The dilution amounts would still be the same. Right?

 

[Rick Mathew]

I would like someone to double/triple check my math.

I would like to make a 0.02N / 0.01M solution of sulfuric acid.

This is where I am at so far:
Starting with a 98% ACS sulfuric acid concentration with a normality of 36.8, I was going to first make a 1000ml solution at 1N by adding 27.2ml to 972.8ml of RODI water.
I was then going to take that 1N solution and dilute it with 49 parts RODI and 1 part 1N sulfuric acid solution to get a 0.02N solution.
So 20ml of 1N solution to 980ml RODI for 1000ml to make a 0.02N solution.

Am I thinking about this correctly or am I missing something super obvious?

Thanks for any input.

Here is a calculator to check your work...I use this all the time...makes life easier

https://www.sigmaaldrich.com/US/en/support/calculators-and-apps/molarity-calculator

 

[Sean Clark]

Here is a calculator to check your work...I use this all the time...makes life easier

https://www.sigmaaldrich.com/US/en/support/calculators-and-apps/molarity-calculator

Thanks for the link Rick.

 

[Rick Mathew]

Thanks for the link Rick.

My pleasure...I use lots of these calculators to do conversions and to make my standards...much like you are doing...let me know how your project works out

 

[Jposch]

so, did you lock up your unit, or nah?

 

[KrisReef]

so, did you lock up your unit, or nah?

I've have been quietly wondering this same thing and wishing someone would follow up with their results.

 

[Sean Clark]

Not yet fingers crossed... Still running strong. I expected issues but nothing yet.

 

[Sean Clark]

I have been getting a few occasional no salt water errors, I assume this is due to wear of the tubing or slippage of the rotor tripping the 191 limit.

 

[Sean Clark]

Hourly testing over a single day with an average of 8.99. 9.0 target. Testing every 4 hours results in more deviation, but still very tight. I am using 100g of sodium carbonate to 900g of RODI for supplement for a 747liter volume.

11/17 20:25:06 W.184 %0 AK.18.00 KH :8.95
11/17 21:43:55 W.186 %0 AK.17.00 KH :8.95
11/17 23:02:12 W.184 %0 AK. 5.00 KH :8.98
11/18 00:20:14 W.184 %0 AK. 0.00 KH :9.02
11/18 01:38:43 W.185 %0 AK. 0.00 KH :9.02
11/18 02:56:30 W.177 %0 AK. 0.00 KH :9.03
11/18 04:14:23 W.178 %0 AK. 0.00 KH :9.03
11/18 05:32:25 W.178 %0 AK. 0.00 KH :9.03
11/18 06:50:22 W.182 %0 AK. 0.00 KH :9.03
11/18 08:09:56 W.184 %0 AK. 4.00 KH :8.99
11/18 09:28:41 W.183 %0 AK.17.00 KH :8.95
11/18 10:47:47 W.185 %0 AK.18.00 KH :8.95
11/18 12:06:30 W.186 %0 AK. 4.00 KH :8.99
11/18 13:25:10 W.181 %0 AK. 0.00 KH :9.03
11/18 14:43:35 W.183 %0 AK. 0.00 KH :9.03
11/18 16:02:10 W.184 %0 AK. 0.00 KH :9.03
11/18 17:20:35 W.186 %1 AK. 3.00 KH :8.99
11/18 18:39:47 W.183 %0 AK.17.00 KH :8.95
11/18 19:58:53 W.186 %0 AK.34.00 KH :8.90

 

[Jposch]

I saw in another thread you have the old f/w.