Australia's Science Forum

Yesterday I made up some phenolphthalein indicator as per B Dungey's The Laboratory i.e. 2g phenolphthalein in 600ml ethanol made up to 1L with distilled water. I noticed that it was bubbling ever so slightly so I left it loosly covered over night, not wanting to seal the bottle with a gas being produced. Today it's still slightly bubbling. There's no visible solid on the bottom. Any thoughts?

what concentration of ethanol did you use?

My recipe is 5g phenolphthalein to 500 mls ethanol and 500mls of water. Stir. I hope this helps.

Any chance there was some residue in the container you used?

If you mix ethanol and water it goes cloudy looking .......lots of tiny bubbles are generated and float to the top . ( I don't know what they are ...perhaps a learned member can enlighten ) ....it also produces a slight heat ( exothermic reaction perhaps )

But it is normally a fairly quick event and after 10 minutes it's all over Red rover .....so not sure why it's still happening next day . So maybe it might have something so do with what Merilyn was talking about .

oh no! If you watch sci fi thrillers - you should be very very very scared!