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Posted

I've been waiting to do titration with a standard solution of HCl to determine the concentration of anhydrous ammonia.

 

Would there be a substitute I could use without a Burette for accurate readings?

 

The one possible choice that I've figured was to manually drop the titrant from a beaker until endpoint but I'm not sure if it would be accurate enough.

 

Does anyone know of any other possible way's to carry out titration without a Burette and being as accurate as possible to a real Burette?

 

Thanks :)

 

 

PS. Burette's are too expensive for me to buy at this time and the concentration of HCl is 0.15 mol/L.

Posted

why would you do a titration of anhydrous ammonia? Anhydrous by definition means that it is free of water, and therefore must be 100%...

Or am I misunderstanding your experiment?

Posted

I'm hoping he means aqueous ammonia...

 

try ebay. You can get a burette for like $20. Or get a good quality graduated syringe. The latter won't really save you much money and the accuracy will suffer.

Posted

well pipette might be of some use but you wont know the titre volume unless the end-point reaches exactly when you have emptied the pipette of the HCl. Also, burette are the most accurate glassware for titration.

Posted

You can add the HCl slowly with a dropping pipette and weigh the solution added. As much accuracy as your balance can give you, but a pain in the neck to do.

 

A decent burette will let you measure to 1% easilly and 0.1% if you are careful and know what you are doing. I think it's a good investment.

Posted
the trouble with weighing is that you will have losses due to evaporation

 

Particularly if you are really working with anhydrous ammonia; but if you use a fairly dilute solution the losses are generally small.

Posted

In AP Biology we generally use syringes or 1ml pipettes, granted that we don't go for a high degree of accuracy, but the calculations work out.

Posted

Whoops, I meant to say aqueous ammonia not anhydrous ammonia :P

 

Wait, since some of you suggested in using pipette, would marking the pipette with calibrated mL lines work for titration so I could determine just how much titrant I used?

 

I've seen many varieties of burettes but the cheaper ones seems to be made of acrylic. About $19 to $25 USD without shipping.

I am eventually planning on buying a glass burette but since it will be much later, I thought that I need a substitute while that time comes.

Posted
Whoops, I meant to say aqueous ammonia not anhydrous ammonia :P

 

Wait, since some of you suggested in using pipette, would marking the pipette with calibrated mL lines work for titration so I could determine just how much titrant I used?

 

I've seen many varieties of burettes but the cheaper ones seems to be made of acrylic. About $19 to $25 USD without shipping.

I am eventually planning on buying a glass burette but since it will be much later, I thought that I need a substitute while that time comes.

 

How will you accurately calibrate a pipette without another method of measuring....You could buy maybe a 5ml mohr pipette (and pipette bulb), but they're rather crude and probably not much cheaper than if you catch a deal on a burette.

 

My burette is kimax glass with teflon stopcock. $20 on ebay...you just need to have patience sometimes and don't go by ebay store prices. :)

Posted

I was thinking of calibrating the pipette by measuring 5mL of water in a graduated cylinder then sucking the fluid through my pipette and mark the bottom of the Meniscus as 5mL. Then continue doing with 10mL and 15mL and so on.

Posted

Do you have a balance? Even one of the cheap ebay ones will give you 0.1g resolution. You can use that to calibrate volumetric glassware (not to ISO standards but, better than a typical measuring cylinder).

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