DIY Alkatronic reagent

[Dennis Cartier]

is there a specific way to test what acid is vs another acid?

This is not my area, but I would expect that the weight of each acid would differ at a given standard. The equivalence point during a titration would also differ for each acid type. The chemistry folks could probably give a better explanation on how to easily identify acid types.

Dennis

 

[Stigigemla]

If You use the M or N value You dont have to think of the weight or % of the acid.

 

[Randy Holmes-Farley]

is there a specific way to test what acid is vs another acid?

what exactly are you asking and why?

As noted above, as long as it is sulfuric or hydrochloric, using a concentration in N (means normal) units, they are the same. Do not use molar units as that gets too confusing for sulfuric acid.

 

[Dennis Cartier]

Ok, I can't sleep. While laying there I started thinking about the 2 different DIY solutions that have been proposed. We have @choooch with 1:4 of 0.1N sulfuric acid and @erky with 1.9 ml of 20 baume muriatic acid added to 1L. So if these are close to correct, than they should be close to each other. Time to test that theory.

I located online the molarity of muriatic acid, https://www.nestgrp.com/protocols/trng/molarity.shtml. The acid that Erky is using is 31.45%, that is pretty close to the line in the chart for 32%, and that would make his acid about 10.2M (equal to 10.2N in this case).

Ok, next is to calculate the dilution that the 2 proposed solutions mix up to. For that we have an online tool https://www.sigmaaldrich.com/chemis...cal-library/solution-dilution-calculator.html.

Entering the values provided by choooch, (1:4 0.1N sulfuric acid), with the target molarity of 0.02M (derived from the 1:4, 0.1N / 5), gives us a 0.25L of the acid to be added to 1L. Which matches what choooch uses. Note, this tool uses Molarity, but for our purposes I am treating Molarity (M) as being equal to Normality (N) because for hydrochloric acid it is. Not so for Sulfuric, but choooch is using a standardized solution anyway (0.1N).

Ok, now to test erky's mixture. Using the same tool, entering hydrochloric acid, with a molarity of 10.2, with 1L as the final volume. Again with 0.02M as the desire concentration (as calculated from choooch). The required volume to add of the acid is 1.96 ml. This lines up with what erky has been using. He is using 1.9 ml, but suggests he is reading high, probably due to the missing 0.06 ml of acid.

They look pretty close to me. I have ordered in the same 4L of 0.1N sulfuric acid as choooch has been using. I still have a couple of months of the OEM acid left, but I will mix up the next batch using the 0.1N to test this solution. I will still have OEM acid in case I need to fall back. I mix up 2L of the reagent at a time, so once this next batch is used up, I can test erky's version next.

 

[Dennis Cartier]

After thinking about this a bit more, and wanting to put the volumetric flasks I purchased at the start of my endavour to figure out what the normality of the OEM acid is, I calculate that adding 10 ml of the 20 baume muriatic acid diluited to 1L with RODI, should give us a base solution of 0.102N. Then mixing 245 ml of the base solution along with RODI to a final volume of 1.25L, should give us a final solution of 0.02N, matching chooch's version. This is predicated on 20 baume muriatic acid actually being 10.2M (or 10.2N). It will be a couple of months before I can test this version.

Dennis

 

[Randy Holmes-Farley]

After thinking about this a bit more, and wanting to put the volumetric flasks I purchased at the start of my endavour to figure out what the normality of the OEM acid is, I calculate that adding 10 ml of the 20 baume muriatic acid diluited to 1L with RODI, should give us a base solution of 0.102N. Then mixing 245 ml of the base solution along with RODI to a final volume of 1.25L, should give us a final solution of 0.02N, matching chooch's version. This is predicated on 20 baume muriatic acid actually being 10.2M (or 10.2N). It will be a couple of months before I can test this version.

Dennis

Note that the 20 Baume acid is likely much less carefully controlled in strength than is something that claims to be 0.10 N. The ones I pulled up from Fisher have certificates of analysis that were like 0.0998 to 0.1002 N . The 20 might be +/- 1 Baume.

 

[Dennis Cartier]

Note that the 20 Baume acid is likely much less carefully controlled in strength than is something that claims to be 0.10 N. The ones I pulled up from Fisher have certificates of analysis that were like 0.0998 to 0.1002 N . The 20 might be +/- 1 Baume.

I was wondering about that. My jug is a commercial 4L muriatic acid. It does show 31.45% and 20 baume, but someone using it to acid wash concrete or other industrial tasks is not going to notice if it is off by a small amount.

I plan to still try it if for no other reason than curiosity. I was also wondering about the strength changing over time of the undiluted acid, even with the lid tightly capped. Using 10 ml at a time from the 4 L, to make the reagent strength required by the Alkatronic, with each refill lasting a month, would mean 1 jug would last me 133 years

Sadly I will not last 133 years ...

Dennis

 

[Stigigemla]

With muriatic acid You will probably have a problem with it evaporating.
So only store it in closed containers made for storing the acid.
Sulfuric acid is a better choice. But if You spill a drop on Your clothes You will probably find a hole there after the next washing. Its problem is that when it is drying only the water is evaporating so it is getting stronger and stronger on that spot.

 

[Dennis Cartier]

I received my 4L of 0.1N sulfuric acid today. I will be mixing up 2L of reagent in the next few days using the 0.1N to test @choooch 's version. Other than the labels, the 2 jugs look identical. Though not indicative of them being the same, at least they are not obviously different on first appearance. I have always expected that the Alkatronic reagent was a white label version of an off the shelf acid standard.

Dennis

 

[erky]

what exactly are you asking and why?

As noted above, as long as it is sulfuric or hydrochloric, using a concentration in N (means normal) units, they are the same. Do not use molar units as that gets too confusing for sulfuric acid.

What i am asking is how can people determine if something is sulphuric acid vs hydrochloric acid, is there a test we can do that acid A produces xyz where acid B does not

 

[Randy Holmes-Farley]

What i am asking is how can people determine if something is sulphuric acid vs hydrochloric acid, is there a test we can do that acid A produces xyz where acid B does not

there are many tests, but not mostly not easy diy at home. Why do you care? It has no functional difference in a titration.

Combining it with calcium chloride solution will likely result in a precipitate from sulfuric acid but not hydrochloric.

 

[Dennis Cartier]

Ok, I have feedback on the 0.1N sulfuric acid standard from Amazon. I mixed up 1.5L of reagent using the Amazon product rather than OEM. I dumped the remnants of the previous reagent just to get a clear test. My last 4 measurements from the previous 24 hours, before swapping in the new reagent, were 7.70, 7.64, 7.70, 7.67. After the new reagent was used, I ran 2 extra measurements. They were 7.56, 7.53. The 0.2 difference between the reagents made from the OEM and Amazon standard is probably caused by a slight mixing error. I overshot on the amount of RODI by 12 ml and tried to add an offsetting amount of acid and then a final correction of RODI, because I overshot on the acid correction . I suspect I either miscalculated, or my scale was is not sensitive enough to small volume changes. Similar discrepancies after slight mixing snafus have happened in the past with the OEM version as well, so I don't consider it relevant.

I think the Amazon 0.1N sulfuric acid is a great alternative to the OEM and plan to use this going forward.

Dennis

 

[Randy Holmes-Farley]

Ok, I have feedback on the 0.1N sulfuric acid standard from Amazon. I mixed up 1.5L of reagent using the Amazon product rather than OEM. I dumped the remnants of the previous reagent just to get a clear test. My last 4 measurements from the previous 24 hours, before swapping in the new reagent, were 7.70, 7.64, 7.70, 7.67. After the new reagent was used, I ran 2 extra measurements. They were 7.56, 7.53. The 0.2 difference between the reagents made from the OEM and Amazon standard is probably caused by a slight mixing error. I overshot on the amount of RODI by 12 ml and tried to add an offsetting amount of acid and then a final correction of RODI, because I overshoot on the acid correction . I suspect I either miscalculated, or my scale was is not sensitive enough to small volume changes. Similar discrepancies after slight mixing snafus have happened in the past with the OEM version as well, so I don't consider it relevant.

I think the Amazon 0.1N sulfuric acid is a great alternative to the OEM and plan to use this going forward.

Dennis

Nice!

 

[Dennis Cartier]

Nice!

Thanks.

To help with future batches, I just ordered a set of larger volumetric flasks that includes a 1000 ml and 250 ml flask to remove the impact of using cheap digital scales.

Dennis

 

[Stigigemla]

I only use very cheap scales and they have worked perfectly for me. I just check that the surface is of plastic as all metals tend to rust by me.
To be certain of the precision I have a set of calibration weights. 0,2 - 1.0 - 5.0 and 20 grams.
I only use tweezer to handle them as fingerprints and all that sticks on fingerprints has a weight.
I recommend to buy from a known chemistry wholesaler and check the tolerance of the weights. I should be 0,1% or better. The weights cost more than the scales.
I have a miniature jewelry scale to 200g that shows better than 0,1 % when I am over 10 g. At 0,2 g it is a bit worse but not much.
I use kitchen scales for up to 5 kg and as I have three, one where i am weighting chemicals + one in the shop and one in the kitchen I test them against each other. The last 10 years or so they have worked perfectly but old scales made of all plastic can detoriate with age. If you buy a scale with litium battery it ought to be safe.
Practically all kitchen scales here in Sweden has the possibility to change units so I think it is the same in the US.
For 10 bucks it ought to be possible to find a good scale capable of switching between pounds or grams

 

[erky]

there are many tests, but not mostly not easy diy at home. Why do you care? It has no functional difference in a titration.

Combining it with calcium chloride solution will likely result in a precipitate from sulfuric acid but not hydrochloric.

i was just wondering

 

[GregOyeah]

Just wanted to confirm a couple things that Im reading in this thread before I attempt to put them into action on my tank

.1N Sulfuric Acid mixed with a 1:4 ration to RODI is an adequate replacement for the Alkatronic reagent solution?

AND

so 500ml Sulfuric Acid mixed with 2000ml of RODI will provide me a new bottle of CONCENTRATED reagent, or mixed and ready to use reagent?

because if this ration provides concentrated reagent, then wouldnt I have to dilute it AGAIN at a 1:4 ration with RODI, so its ready to use with my alkatronic?

Also, just wanted to confirm, its still safe to dump waste water back in your tank with this recipe? it seems so after reading the thread but just wanted to confirm.

Great thread and thanks for the replies everyone.

 

[Dennis Cartier]

Just wanted to confirm a couple things that Im reading in this thread before I attempt to put them into action on my tank

.1N Sulfuric Acid mixed with a 1:4 ration to RODI is an adequate replacement for the Alkatronic reagent solution?

AND

so 500ml Sulfuric Acid mixed with 2000ml of RODI will provide me a new bottle of CONCENTRATED reagent, or mixed and ready to use reagent?

because if this ration provides concentrated reagent, then wouldnt I have to dilute it AGAIN at a 1:4 ration with RODI, so its ready to use with my alkatronic?

Also, just wanted to confirm, its still safe to dump waste water back in your tank with this recipe? it seems so after reading the thread but just wanted to confirm.

Great thread and thanks for the replies everyone.

As long as the sulfuric acid standard you are using is 0.1N, then yes, mixing 1:4 with RODI will give you mixed and ready to use reagent. I am not sure about dumping back in the tank (I use a drain under my Alkatronic), but I think it is fine. I am sure others will chime in on that aspect.

Dennis

 

[GregOyeah]

As long as the sulfuric acid standard you are using is 0.1N, then yes, mixing 1:4 with RODI will give you mixed and ready to use reagent. I am not sure about dumping back in the tank (I use a drain under my Alkatronic), but I think it is fine. I am sure others will chime in on that aspect.

Dennis

Ok just want to confirm, and I apologize for the redundancy but when you say ready to use, you mean it’s ready for the Alkatronic to use, meaning it’s not a concentrated reagent that needs to be diluted again?

 

[Dennis Cartier]

Ok just want to confirm, and I apologize for the redundancy but when you say ready to use, you mean it’s ready for the Alkatronic to use, meaning it’s not a concentrated reagent that needs to be diluted again?

Correct. Ready to be used in the Alkatronic.