24 replies to this topic

[YIC]

I need to keep this beaker (which will contain a test tube which will be connected to other apperatus) at a constant temperature. I can use a water bath for high temps (well, above room temp anyway). However, I need one for low temps and I can't use a water bath or a fridge / freezer.

I am thinking of constantly running the beaker under a tap of cold water so that the temp stays the same.

(any more suggestions?) I am also thinking of putting in ice cubes but I know the temp will not be constant

[dondon]

Something like the apparatus for distillation would be good so you could have a constant flow of water, and it wouldn't be sitting and raise to room temperature.
The ice cubes would work but only really for a short experiment if its going to be any longer than a couple of minutes then the temperature would gradually raise.

[YIC]

my experiment will last for 1 minute, so do you think ice cubes will be okay?

Edited by YIC, 06 September 2005 - 06:21 PM.

[dondon]

it should be, if there is any change in temperature it will me incrediby small but to show that the temperature is constant you could put a thermometer in the ice. You could check with your teacher first though, if its not a test or something.

[YIC]

is it possible to take an average temperature? (e.g. if it is at 3 degrees and moves up to 4 degrees, could I say I did the expt at 3.5 degrees?)

sorry for the questions

[dondon]

probably not because they will want it to be very accurate. To minimise the change you could put the ice in cold water or you could bend the truth a little bit and say it stayed the same. But even if it does change it will be very small. And you could test it first and out ice in a beaker and measure the temperature at the beginning and then after a couple of minutes to see the change.

And I don't mind, its giving me something to do

[YIC]

do you think putting the ice cubes in the cold water would keep the temp at bay?

[dondon]

I think so because my chemistry teacher from last year always did that and she said it kept the temperature nearly competely constant even when we did quite long experiments. Putting salt in with the ice usually does somthing about it too but that melts the ice, lowering the temperature.

edit: so probably that isnt a good idea

i'm tempted to go through to the kitchen and try lol

Edited by dondon, 06 September 2005 - 06:37 PM.

[YIC]

cool thanks then Do you think I should still use my tap mecahnism thingy I mentioned at the start? (i.e. filling the beaker with cold water constantly, making it overflow)

that is the lasst question hopefully


edit: I do realise the distillation thing you were saying, but that might be too complicated for me

Edited by YIC, 06 September 2005 - 06:41 PM.

[dondon]

You could try with the ice first and not actually do the experiment but see if the temperature changes in any major way.
The tap idea is good though because the warm water would rise to the top and overflow.
Oh, and does the experiment give out or take in heat?, because that would affect the temperature of the ice, but it would be ok if you used the water because it would be constantly flowing.

[dondon]

the distillation thingy would be difficult to get working but just letting the water overflow out of some kind of container that the beaker/test tube is in would be just as good. Well i think so.

[YIC]

You could try with the ice first and not actually do the experiment but see if the temperature changes in any major way.
The tap idea is good though because the warm water would rise to the top and overflow.
Oh, and does the experiment give out or take in heat?, because that would affect the temperature of the ice, but it would be ok if you used the water because it would be constantly flowing.

It is actually an experiment to do with hydrogen peroxide being broken down into oxygen and water. I don't think there is any temperature change

[dondon]

I don't think there is any temerature change, i'm assumong its catalase you're using because when you use an enzyme usually there is no temperature change.

[YIC]

I don't think there is any temerature change, i'm assumong its catalase you're using because when you use an enzyme usually there is no temperature change.

yeh it is catalase...thanks a lot for the help

[dfx]

Dayumn. Atomic geek then donna are we?

[YIC]

oooooh, prepare for a slap dfx











(not from me though)

[dondon]

Dayumn. Atomic geek then donna are we?

oooh!! If only I was in a bad mood then i would just have to slap you!

and yes it seems so

this time you never got to give a better answer than me

[dondon]

oh i forgot to add muahahahaha!!!











i'm in a very strange mood

[dfx]

ur scarin me!

*runs and hides*

[dondon]

good! lol

It's ok though im not in an evil mood today so you don't need to hide