Is It Just Me?

[Bert45]

There are at least two TV programmes ( This Morning - Lynsey Crombie "Queen of Clean" and Filthy House SOS) where they recommend sodium bicarbonate and lemon juice or vinegar as home-made cleaners. They seem to believe that the fizz and bubbles show the 'magic' power of the mixture. Has nobody been able to tell them that the cleaning agent is the acid in the lemon juice or vinegar, and that they are neutralising it by adding sodium bicarbonate? The crystals of bicarbonate may help a little to begin with, until they dissolve in the aqueous solution, but other than that, it serves no useful purpose. Or is it just me?

[theprof]

No it's not you. It's them.

In simple terms, adding bicarb to vinegar produces a solution of sodium acetate, water with the production of carbon dioxide.
Let's look at these one by one.

The sodium acetate produced doesn't all go into solution despite being very soluble in water. You'll see it as a small amount of white powder in the mixture after the reaction is over. Powders of this type are abrasive to an extent in water.

Water has always been known as the universal solvent and is a powerful cleaning agent in itself.

Unless this the amount of dry bicarb in grams and vinegar in millilitres is calculated very carefully, vinegar may well remain in the final solution. Years ago, laboratory demonstrators used to demonstrate this by getting the students to carefully sniff the top of a beaker after the reaction between the bicarb and vinegar subsided. Invariably, they could still detect a vinegar odour.

So what does this all mean? Well, after the reaction you have a universal solvent, an abrasive powder and another powerful cleaning agent (vinegar) in the resulting solution. You might as well tip salt/fine rock salt/sea salt into water with a few splashes of vinegar for the same effect. Lots of people seem to use these ingredients separately. It's the fact that it fizzes just seems to give the impression that it's powerful. It's not.

[Peter Pedant]

oh er right
good afternoon prof
life treating you well I hope

[Vagus]

You do have a great way of explaining things in quite simple terms, theprof, which is great, thanks :)

[gingejbee]

However, there could be a psychological effect to this...lots of froth(equating it with detergent foam) means it's doing a good cleaning job.

[theprof]

Peter, good afternoon. Yes, life is OK at the moment. Back at uni right now but I still mooch around in PD now and again. They've even given me a new laboratory with no expenses spared! I must have done something right. During the few spare hours I've got, I'm editing the draft of a new textbook on plant biochemistry for a publisher with my red pen at hand!

Vagus, thank you. I'm very grateful. I know my answer took up quite a few lines but it was as concise as I could make it.

[theprof]

gingejbee, you make a good point but it's not true.

It's as well to remember that citric acid and sodium bicarbonate are some of the dry ingredients in Andrew's Salts antacid (aka Andrew's Liver Salts for those of us not in our youth).

Years ago, people were told to put a spoonful or two of the Andrews powder into a glass of water and drink it while it was "fizzing" or it wouldn't work as well. It was a myth and didn't make any difference. The same applied to "Eno" salts and others.

I don't think people think in terms of detergent with the vinegar/bicarb mix for the above reason. It's just that anything that froths seems more powerful. Kids eyes open wide when they see any reaction that froths in a laboratory.

[Canary42]

It's because, thanks to relentless marketing, the General Public now chooses style over substance. It fizzes a lot (although achieving little effective action) so it must be good.

Bit like the PM

[bhg481]

Isn't the same true of the detergent in your washing machine? People think you need lather for it to work and the more the better; not true.

[douglas9401]

Not sure if you mean Mr J is full of pep and vigour or if 'fizz' is being used as a replacement to pass the censor. :-P

[jourdain2]

It's them. I'm allergic (asthmatic reaction) to most commercial cleaning products (don't put me within a mile of conditioning sheets for tumble-dryers!) and I live in a very, very hard-water area. It leaves a horrible black deposit within a week - I use white vinegar mainly and firstly. I empty a bottle into a sprayer to get coverage & leave it for a minute. A wipe down with a cloth and warm water sorts most of the rest of it.

[Atheist]

I get a slow build-up of black mould in patches here and there on the grout in my shower; it takes a couple of months to become noticeable, but when it does I treat it with a paste made of soda bicarb and a tiny amount of vinegar (no big fizzes or bangs!). Because it is a paste I can use an old toothbrush to apply it to the spots where it appears and then leave it for a couple of hours before scrubing it away. It works well. The pasty consistency helps it stay in place while it does its work.

[Arksided]

Cleaning stuff, what is this voodoo magic you speak of.