need sodium hydroxide

[Maylar]

I have a TA test kit that uses sodium hydroxide 0.2N as a reagent. I need more of it, and all I can find is 0.1N. Anybody know the difference, or where I can find 0.2N?

(I'm an EE, not a chemist)

Thanks

 

[kh54s10]

Google search: https://www.amazon.com/Sodium-Hydroxide-0-2N-0-2M-100ml/dp/B01LZ1LS88

 

[bpinto]

I've bought some supplies from Carolina before too:

https://www.carolina.com/specialty-...s-laboratory-grade-500-ml/889557.pr?question=

 

[IslandLizard]

Or compound your own...

 

[jgmillr1]

I have a TA test kit that uses sodium hydroxide 0.2N as a reagent. I need more of it, and all I can find is 0.1N. Anybody know the difference, or where I can find 0.2N?

(I'm an EE, not a chemist)

Thanks

I'm an EE too, but I attempt chemistry on TV. You'll get more accurate results using the 0.1N formulation since you can more easily measure a larger volume. You just end up using twice as much.

0.2N means 0.2 molar concentration. Since NaOH is 40g/mole, this means you can make your own soln with 8g per liter of distilled water. I buy NaOH from Amazon and make my own soln.

 

[RPh_Guy]

I'm an EE too, but I attempt chemistry on TV. You'll get more accurate results using the 0.1N formulation since you can more easily measure a larger volume. You just end up using twice as much.

0.2N means 0.2 molar concentration. Since NaOH is 40g/mole, this means you can make your own soln with 8g per liter of distilled water. I buy NaOH from Amazon and make my own soln.

+1
I'd use 0.1N and adjust the calculation accordingly.

@jgmillr1 Do you know the shelf stability of solid NaOH? I think the solution is only good for 6-12 months.

 

[jgmillr1]

@jgmillr1 Do you know the shelf stability of solid NaOH? I think the solution is only good for 6-12 months.

I mainly use the sodium hydroxide for cleaning. A10# jug of the solid chemical lasts me something like 9 months. It will absorb water (hydroscopic) over time. I find that when I make a batch of 0.1N soln, I have to fine tune it at the end by titrating a known acid and tweaking the strength of the NaOH soln or living with 0.12N.

It's probably easier to buy the soln from your lhbs, but I figure I have the stuff so I might as well make it. Besides you never know how long their stuff has been sitting on the shelf. And I usually run out when I need to run a bunch of titrations.