Acid/Base stock solutions

Post by **RosalieM** » 03 May 2007, 12:53

Hi All,
I was just wondering what concentrations of acids and bases people stock in the lab. Up until now I've just been making up solutions as requested but this isn't always convenient so I would like to make some larger quantities to keep handy.
Thanks,
Rosalie

Post by **Robb** » 03 May 2007, 13:23

Hi RosalieM,

I have the following:

Hydrochloric Acid - 5 Molar, 2 Molar, 1 Molar, 0.5 Molar (all of which are 2.5L volumes).

Sulfuric Acid - 5 Molar, 2 Molar, 1 Molar, 0.5 Molar (all of which are 2.5L volumes).

Nitric Acid - 2 Molar (all of which are 2.5L volumes).

Sodium Hydroxide - 2 Molar, 1 Molar, 0.5 Molar, 0.1 Molar. (all of which are 2.5 L volumes).

Ammonium Hydroxide - 2 Molar. (2.5L)

bullster · Post by **bullster** » 04 May 2007, 08:55

Hi,
I keep:

2.5L 2M Sodium Hydroxide
2.5L 1M Sodium Hydroxide
2.5L 2M Hydrochloric Acid
1L 2M Sulfuric Acid
1L 2M Nitric Acid

These are the most commonly used solutions at our (small) school.
I also have a range of other concentrations in volumes ranging from 100mL to 1L.
I've engraved my 2.5L bottles at appropriate places so that I can use them like a volumetric flask- this now saves a bit of fiddling around.

I use a syphon on my bottle of 2M HCl for speedy filling of dropper bottles. This is a bit clumsy but OK.
What do other people do for efficient decanting????

Xenon · Post by **Xenon** » 04 May 2007, 09:24

Hi, this suits me (and works well at this school)

HCl & H2SO4: 4M, 2M, 1M, 0.5M, 0.1M. Prepare each by diluting the next most concentrated, so the 4M is only one prepared from the conc.

HNO3 & NaOH: 1M & 0.1M (other strengths made up only when requested)

NaOH is nasty stuff, precipitates with age >1M ; cannot store in glass-stoppered bottles and rots dropper bottles (I have nothing stronger than 0.1M in these).

Post by **RosalieM** » 04 May 2007, 11:58

Hi all,
Thanks for your responses. I've now got most of my concentrations made up (it has been a quiet day

). As for pouring it into dropper bottles, what I have been doing so far is pouring it into a beaker or small measuring cylinder and then using a funnel, pouring it into the dropper bottles. Not an efficient method and it creates extra washing up!! So I would be willing to read about any other methods of transfer as well.
Rosalie

Robbie · Post by **Robbie** » 04 May 2007, 12:18

Greetings all,

We also use Acetic Acid and Potassium Hydroxide as well as the ones Robb mentions.

When pouring into dropper bottles I use a plastic jug which has an excellent pouring spout and a handle (Q Stores 2006 Catalogue p196, item 2504243). This is very easy to hold and is one less piece of glassware to get broken.

We bought plain screw tops for the 50ml dropper bottles, as well as the dropper assemblies. When in store use the plain tops and only replace them with the dropper tops when being used. Saves a lot of perished rubber droppers. I have found the worst offender for rotting the droppers is vinegar (acetic acid)!

Always good to hear what others are using and doing!

Cheers,

Robbie

marilynm · Post by **marilynm** » 04 May 2007, 17:03

Hello
Robbie from Asquith NSW mentioned that he has plain screw tops for his dropper bottles and only attaches the dropper assemblies when required.
I use non/pererishable droppers from Silverlock (VIC/SA/WA)
I find that I only need to change probably 20 tops a year out of over 1000 tops!
They come in a variety of sizes and colours and weigh very little so postage between states would not be too expensive.
Worth a look.
Marilynm

Robbie · Post by **Robbie** » 07 May 2007, 10:42

Hi Marilyn,

Thanks for the info. That is worth looking into. It would save doubling up on stoppers/lids.

By the way, I'm a her not a him

I'm actually surprised, impressed at the number of labbies who are males - it used to be an all female domain!

Cheers

Robbie (Robyn)

fibreweb · Post by **fibreweb** » 08 May 2007, 15:17

Oxley High is a big spread out school with 3 preprooms. My main prep room and 2 others each up several flights of stairs. To elimate carrying solutions to and fro I have a 2.5 Litre stock bottle of 1M
Hydrochloric acid
Sulfuric acid
Acetic acid
Nitric acid
Ammonia
Lime water
Sodium Hydroxide in each of the other prep rooms
I also have a class set of 10 125/250 ml reagent bottles of each of these solutions in the prep rooms.

In my main prep room I have winchesters of 2M and 4M HCl and H[sub]2[/sub]SO[sub]4[/sub] and dilute solutions of HCl and NaOH. I have a special carrier that holds a winchester for when I need to replace one of the 2.5 litre bottles in one of the other rooms.

Wendy

Post by **Labbie** » 06 Sep 2007, 10:30

marilynm wrote:Hello
Robbie from Asquith NSW mentioned that he has plain screw tops for his dropper bottles and only attaches the dropper assemblies when required.
I use non/pererishable droppers from Silverlock (VIC/SA/WA)
Worth a look.
Marilynm

Has any one been able to purchase the Non Pererishable droppers in NSW? Would someone be able to give me Silverlock's address etc.

Many thanks

Bob · Post by **Bob** » 07 Sep 2007, 18:10

Google Silverlock and look at their contact list.

Bob

Post by **Labbie** » 10 Sep 2007, 08:39

Bob,

Thank you for your help.

Regards

Post by **Slartibartfast** » 10 Sep 2007, 09:45

For decanting into dropper bottles I run the solution down the dropper itself into the bottle directly from the 1 litre storage bottle (which is kept full from a winchester) This is an old modeling trick for adding metho to very small (10-20ml) paint tins. No washing up and no spills ever. With the lip of the decanting bottle placed against the glass of the dropper, pour carefully and it will run directly into the dropper bottle without spilling any of it. Tooooooooooo easy!

cactus155 · Post by **cactus155** » 10 Sep 2007, 10:03

I think this should fit into another forum maybe Chemistry and Labware rather than Biology/Physics. Just a thought

Post by **Slartibartfast** » 10 Sep 2007, 10:57

Quote from above: I use a syphon on my bottle of 2M HCl for speedy filling of dropper bottles. This is a bit clumsy but OK.
What do other people do for efficient decanting????

Why should I start another forum answering another from above? As in conversations, forums flow - deviating from the topic sometimes. Do people read all the postings in the forums or just the last ones? Just a thought

estelle · Post by **estelle** » 10 Sep 2007, 12:27

I pretty much read all the forum, pick up more info that way.
Estelle

Post by **Slartibartfast** » 10 Sep 2007, 12:32

I always do. There's too much you miss otherwise and it's apparent in the things people write.

Post by **RosalieM** » 10 Sep 2007, 13:52

I guess I can take responsibility for this being in the wrong section as I wrote the initial post. I'm pretty sure it was back in my early Chemtalk days and I probably just hit the 'new topic' button in the last forum I was reading, which automatically puts the new post in that topic. I have since learnt more about Chemtalk and try to put my posts in the right sections.
Rosalie

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