Life span of Sodium Hydroxide

A general discussion and Q & A forum.
Post Reply
User avatar
Nichole
Posts: 15
Joined: 24 Jun 2014, 14:07
School: Bonnyrigg High School
State/Location: NSW

Life span of Sodium Hydroxide

Post by Nichole »

Hi everyone
How long do you keep your sodium Hydroxide stock bottles for?
Do you also keep them in a dark glass bottle
Reason for asking is Head teacher has said to throw anything older than 3 mths out and I have done a google search where I found out sodium hydroxide should be stored in a plastic bottle not in glass.
:rules:
linotas
Posts: 659
Joined: 21 Mar 2011, 22:39
State/Location: TAS

Re: Life span of Sodium Hydroxide

Post by linotas »

I keep mine for longer then 3 months...although it does not hold its molarity long. If I need standardised naoh I re standardise if it is only than a month or so. Mine is stored in whatever I have on hand.

Molten NaOH will dissolve glass so I suppose in soution it may have some effect but I have never heard of not storing it in glass.
Merilyn1
Posts: 1476
Joined: 12 Mar 2013, 08:10
Job Title: Labbie
School: Wollondilly Anglican College
Suburb: Tahmoor
State/Location: NSW

Re: Life span of Sodium Hydroxide

Post by Merilyn1 »

I've only heard of not storing it in glass with a glass stopper - but who has those these days?
User avatar
Labbie
Posts: 3234
Joined: 28 Nov 2006, 10:00
Job Title: Retired
Suburb: At Home
State/Location: NSW

Re: Life span of Sodium Hydroxide

Post by Labbie »

Its is ONLY the solid form that must be in a plastic bottle NOT GLASS Soultions can go into glass with out a glass stopper.
Regards Labbie

Lab Manager/Lab Tech, mind reading etc etc
Now retired :wub:
User avatar
Ian
Posts: 575
Joined: 16 Oct 2006, 10:00
Job Title: Lab Assistant
School: Macarthur Anglican School
Suburb: Cobbitty
State/Location: NSW

Re: Life span of Sodium Hydroxide

Post by Ian »

What are you using it for? I would make up fresh solutions for senior titrations, etc, but for juniors to play with, I keep it until it is all used up! (I have a stack of 250mL reagent bottles) After a year or so, it might precipitate out "gunk" and turn the inside of the reagent bottle translucent, but if still turns litmus blue and will neutralise HCl.

When the stock bottle is empty, I swish it well with 1M HCl and rinse it well and the milky glass reagent bottle will be as good as new!
User avatar
Lyn
Posts: 706
Joined: 16 May 2006, 10:00
Job Title: Lab Assistant (Technician)
School: St. John's Catholic College
Suburb: Darwin
State/Location: NT

Re: Life span of Sodium Hydroxide

Post by Lyn »

Same as Ian. Fresh solutions for the senior chemistry and use up the leftovers and old stock for the junior classes. If the sodium hydroxide precipitates in the bottom of the bottle I decant what I can and neutralise the rest before sending it down the drain. My stock of NaOH is stored in glass bottles with plastic stoppers. (If you use glass stoppers you can't get them out. They freeze up.) I don't use these bottles for any other solutions. I use glass stoppers for my 250 and 500ml acid bottles. Yes I have very old bottles which still have glass stoppers but I am gradually adding new bottles with plastic stoppers.
Post Reply