Drano

[Xenon]

We have a yr9 Assessment Task where household chemicals are tested with home-made indicators. One of the listed products is Drano which is 54% NaOH, User Code 11-12 in the CSIS Appendix D (though may be used under 'close supervision' for soap and paper making activities ONLY. Solutions stronger than 1M are seniors or Tch (>4M) so I give them <1M (4%) solution in dropper bottles, which is far removed from the original intention of testing household products. If anyone else has come across this, what do you do, or are eyeballs rolling upwards everywhere?

[Robb]

Hi Xenon,

This is always a touchy subject as you already know!! But if the Drano is used in small quantities then this should not be an issue.

If the tests are involving indicators then a safer more efficient way would be to add a few grains to a test tube, hence already preparing it, then issuing the test tube out rather than the Drano.

This way it reduces exposure to the Drano and gives the students a more realistic Kitchen Chemistry feel to the experiment.

Using this technique should not be a problem and you have reduced exposure and made a potential hazardous situation quite feasible and safe..

Hope this helps..

Robb........

[worktofish]

To all intents and purposes both the drano neat and diluted will both achieve the same pH. Give it to them diluted and dont tell them.

[Robb]

Hi All,

Just keep in mind that if there is an accident then you would then be liable. There always label what you make.

One other consideration to also take on board, that being - Sodium hydroxide does not produce systemic toxicity, but is very CORROSIVE and can cause severe burns in all tissues that it comes in contact with.

Sodium hydroxide poses a particular threat to the eyes, since it can hydrolyze protein, leading to severe eye damage.

Hope this helps,

Robb.......

[ri]

Hi All,
please bear in mind that, if just about ANY concentration of sodium hydroxide (Drano) gets into anyone's eyes (ie. if they are NOT wearing safety glasses), you only have SECONDS in which to act.
Get the person to a safety shower or eyewash station and wash the eye for at least 15 minutes with running water. Then off to a medical centre for a doctors opinion.
If the cornea gets 'burnt', only a corneal transplant will fix it and that takes a person to die to donate one.

[Rita]

Hi Xenon
What other household chemicals do you use?
We only prepare and use the red cabbage indicator. Would be pleased to know of any other home-maade indicators. The chemicals we use are things like shampoos, bottled lemon juice and dilute bleach.
Cheers,
Rita

[louie]

Hi ! Surely there are a miriad of other household bases they could test? How about washing powders eg Omo , the cheapest laundry soap you can find -scrape a few peelings off it, cloudy ammonia etc. I couldn't let them have grains of drano here ! It would be an accident waiting to happen. But then I've side tracked the teachers onto alternatives before ..so I guess they are used to it. I see your problem.

[Jazz]

Hi,
Hoe you can use this one

RAINBOW EXPERIMENT
Equipment:
Large measuring cylinder (1L)
Sodium Carbonate (washing soda)
Vinegar
Long stirring rod
Universal indicator

Method:
Fill measuring cylinder (3/4) with water
Stir approximately 10mL of universal indicator
Add 30 gr washing soda
Add about 80 mL vinegar
Stir with rotating action
Adjust quantities if different size cylinder is used

The cylinder will keep layers for days (this is diffusion experiment diffusion of the Sodium carbonate is slow), but it will work for pH as well cause adding vinegar or washing powder is obvious pH cahange

[Xenon]

Thanks All, for suggestions and info. I might just re-label some dilute NaOH as "Drano" next time, Wink (with appropriate warnings, of course).

Rita - we use similar products, and OJ, Jiff. Perfume is on our list but I substitute lemon essence. I make up and keep long-life red cabbage indicator in fridge. Some students make their own, others bring in beetroot juice or tea (no milk or sugar).

cheers,

Xe

[Ocean Breeze]

For home made pH indicator... we use the red cabbage, as well as tibouchina flowers. They work a treat. They can be frozen until needed for later, and lose none of their colour change properties O:)

[smiley]

We also make a home-made indicator out of hibiscus flowers. When they're out of season, or if you don't live in the tropics, then herbal teas containing hibiscus, such as a rose-hip and hibiscus tea, works really well and is very easy to prepare.

Smiley