Hydrochloric Acid

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kimmy
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Hydrochloric Acid

Post by kimmy »

My conversion brain just does not want to work today :banghead2:

I have extra 1m Hydrochloric Acid and need 2m

How much 32%concertrate do i need to add to change from 1m to 2m

1m is 100ml to make 1litre

Thanks in advance for whoever has this worked out for me. :thumbup:

I just keep getting different answers when trying to work out. :crazy: :crazy:
MariaQ
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Re: Hydrochloric Acid

Post by MariaQ »

This is tricky, because you dont have a blank to start with, Id just label it 1M and make up another batch of 2M, much easier process! MariaQ
Merilyn1
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Re: Hydrochloric Acid

Post by Merilyn1 »

I agree. I've never done this and actually got told really early on to not do it. Best to start again. If you don't have anything stronger that you can dilute, maybe ask one of your local labbies if you can "borrow" and payback. If it is only for juniors, you can buy 32% HCl in Bunnings.

Bad Day: I missed that you had the concentrate. It still sounds like too many numbers for me. I'd just cheat and start again. I'd save the 1M and dilute it down to 0.1M as you needed it. Do your Chem students do titration - always go through a bit with them.
Last edited by Merilyn1 on 16 Feb 2021, 13:34, edited 2 times in total.
bigmack
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Re: Hydrochloric Acid

Post by bigmack »

So 2M is 200mls per liter .
If you had 500lms of 1M it would contain 50mls HCl and 450mls of water
Therefore you would need to add 150mls of HCl and 350mls of water to make it up to a liter .

If you had 750 mls of 1M it would contain 75mls HCl and 675mls of water .
Therefore you need to add 125 mls HCl and125mls of water .

If you had 800mls of 1M it would contain 80mls of HCl and 720mls water
Therefore you need to add 120 mls HCl and 80mls of water .

If you had 850mls of 1M it would contain 85mls of HCl and 765mls water
Therefore you need to add 115 mls HCl and 35mls of water .

If you had 875mls of 1M it would contain 87.5mls of HCl and 787.5mls water
Therefore you need to add 112.5 mls HCl and 12.5mls of water .


If you had 885mls of 1M it would contain 88.5mls of HCl and 796.5mls water
Therefore you need to add 111.5 mls HCl and 3.5mls of water .

If you had 890mls of 1M it would contain 89.0mls of HCl and 801mls water
Therefore you need to add 111 mls HCl and -1mls of water .

So add 111mls of 32% HCl to 890mls of 1M HCl should bring it up to 1 litre of 2M

My math brains not working either . I'm sure there's an easy formula to work this out :-(

Edit:
Actually , the more I think about it , it is very similar problem that Vinters have when they need to Fortify wine by adding a stronger strength alcohol .
I believe that it's a mathematical procedure called a Parsons square which is used to derive the answer . There are online calculators that work it out .Suely there would be one for this type of application too .
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Anastasia
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Re: Hydrochloric Acid

Post by Anastasia »

I'm thinking:

C1 x V1 = C2 x V2

To make up 100ml of 1M (32% HCl assumed to be 12M)
12 x V1 = 1 x 0.1
V1 = 8.33ml
So the 100ml of 1M HCl contains 8.3ml 32% HCl

To make up 1L of 2M
12 x V1 = 2 x 1
V1 = 166.66ml
So the 1L of 2M HCl should contain 166.66ml 32% HCl

But you already have 8.33ml of it in the 1M solution
166.66 - 8.33 = 158.33ml

Add 158.33ml of 32% HCl to the 100ml of 1M solution then make up to 1L and you should have the 2M concentration
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Lyn
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Re: Hydrochloric Acid

Post by Lyn »

My first response this morning when I read this was just make up a fresh batch of 2M and be done with it. My second response after reading all the advice above is: " make up a fresh batch of 2M and stop stressing out". My head hurts after reading the above two answers. :-? Is it :coffee: time?
Merilyn1
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Re: Hydrochloric Acid

Post by Merilyn1 »

Lyn wrote: 16 Feb 2021, 15:37 My first response this morning when I read this was just make up a fresh batch of 2M and be done with it. My second response after reading all the advice above is: " make up a fresh batch of 2M and stop stressing out". My head hurts after reading the above two answers. :-? Is it :coffee: time?
Yep. Agree.
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kimmy
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Re: Hydrochloric Acid

Post by kimmy »

bigmack wrote: 16 Feb 2021, 11:47 So 2M is 200mls per liter .
If you had 500lms of 1M it would contain 50mls HCl and 450mls of water
Therefore you would need to add 150mls of HCl and 350mls of water to make it up to a liter .

If you had 750 mls of 1M it would contain 75mls HCl and 675mls of water .
Therefore you need to add 125 mls HCl and125mls of water .

If you had 800mls of 1M it would contain 80mls of HCl and 720mls water
Therefore you need to add 120 mls HCl and 80mls of water .

If you had 850mls of 1M it would contain 85mls of HCl and 765mls water
Therefore you need to add 115 mls HCl and 35mls of water .

If you had 875mls of 1M it would contain 87.5mls of HCl and 787.5mls water
Therefore you need to add 112.5 mls HCl and 12.5mls of water .


If you had 885mls of 1M it would contain 88.5mls of HCl and 796.5mls water
Therefore you need to add 111.5 mls HCl and 3.5mls of water .

If you had 890mls of 1M it would contain 89.0mls of HCl and 801mls water
Therefore you need to add 111 mls HCl and -1mls of water .

So add 111mls of 32% HCl to 890mls of 1M HCl should bring it up to 1 litre of 2M

My math brains not working either . I'm sure there's an easy formula to work this out :-(

Edit:
Actually , the more I think about it , it is very similar problem that Vinters have when they need to Fortify wine by adding a stronger strength alcohol .
I believe that it's a mathematical procedure called a Parsons square which is used to derive the answer . There are online calculators that work it out .Suely there would be one for this type of application too .

thank you
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kimmy
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Re: Hydrochloric Acid

Post by kimmy »

Merilyn1 wrote: 17 Feb 2021, 06:47
Lyn wrote: 16 Feb 2021, 15:37 My first response this morning when I read this was just make up a fresh batch of 2M and be done with it. My second response after reading all the advice above is: " make up a fresh batch of 2M and stop stressing out". My head hurts after reading the above two answers. :-? Is it :coffee: time?
Yep. Agree.
that normally would be my response but i had 5 x 1litre in 1m so I was basically just trying to use it up instead of wasting it as I would not use that much 1m in ages.
got it worked out so all good now.
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kimmy
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Re: Hydrochloric Acid

Post by kimmy »

Thank you to those who replied.
Yes normally I would just make up more but considering the amount of 1m that I had i was just trying to use it up.

Got it sorted now thank you again for the responses.
Merilyn1
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Re: Hydrochloric Acid

Post by Merilyn1 »

A braver person than me! :D
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