Many advertisements claim that combining the cleansing powers of vinegar and baking soda creates a powerful, all-purpose cleanser. But is that true? Ask Science is on the case.
Andrea, a faithful Ask Science listener, recently wrote in with this question:
“I have used vinegar and baking soda separately for cleaning parts of my home, and they work great. But lately I've seen "Amazing All-Purpose Cleanser"-type recipes on the internet that call for vinegar and baking soda to be combined, which supposedly can clean everything from your kitchen sink to your Grandma's dentures. My question is: Don't vinegar and baking soda just neutralize each other? That's what I learned in school when we did the good old volcano experiment. Was my teacher wrong? Am I missing out on the best cleanser of all time?”
That’s a great question Andrea.
A Rose by Any Other Name…
Before we answer Andrea’s question, let’s reveal the secret identities of these cleansing substances. Baking soda has a lot of unofficial sciencey names that you might have heard before, like sodium bicarbonate or bicarbonate of soda. However its true identity (according to scientists that have been put in charge of naming chemicals) is “sodium hydrogen carbonate.”
There are lots of different kinds of vinegar depending on what ingredients are used to start the fermentation process that produces it. For example, apple cider vinegar starts out with apple cider while rice vinegar uses rice. No matter what you use to make vinegar, the end product can be distilled to make what is commonly called “white vinegar.”
Distilled or white vinegar is a mix of acetic acid and water. The amount of acetic acid in vinegar is important to know because it’s the acetic acid that gives vinegar its powers. Acetic acid strength is measured in “grains.” 10-grain vinegar means vinegar made of 1% acetic acid and 99% water. The most common household vinegars are 50-grain, meaning 5% acetic acid and 95% water.
Let’s Get Chemical, Chemical
The low pH of acetic acid makes vinegar an excellent cleaner. Cleaning experts recommend its use for polishing metal, cleaning mildew from tile, sanitizing your garbage disposal, and removing calcium deposits. Just ask my fellow Quick and Dirty Tips expert, the Domestic CEO; she’ll tell you. Also, Ancient (and some modern) physicians even used vinegar to cleanse the inside of the body.
Sodium hydrogen carbonate (aka baking soda) is a base. Bases are also good cleaners, and baking soda in particular seems to have no end to the things it can be used for. It’s been recommended as an air freshener, antacid, carpet cleaner, toothpaste, and more.
Since both of these things are such good cleaners separately, surely mixing them together will provide even better results. Right?
Danger, Will Robinson!
Let me stop here to give a general warning:
Don’t mix chemicals unless you know what you’re doing!
In the case of baking soda and vinegar, the results are harmless. But other mixtures, like ammonia and bleach, can create toxic and even explosive results.
So what exactly happens when you mix vinegar and baking soda? Since vinegar is an acid and baking soda is a base, they undergo an acid-base reaction. Now there are a couple of different theories that scientists use when discussing acid-base reactions, but generally when an acid and a base are mixed together, the result is that the acid and base neutralize each other to form water and a small amount of salt.
In the case of vinegar and baking soda, the acetic acid and sodium hydrogen carbonate combine to form water, carbon dioxide (which is responsible for all the bubbles), and sodium acetate.
But Will it Work?
So now you have a cleaner made of sodium acetate and water, so what’s it good for? Sodium acetate itself has lots of uses. Most deliciously, it provides the salt and vinegar taste of potato chips. It is also used to make instant hot packs and heating pads and it’s useful as a chemical buffer that resists pH changes. Try as I might though, I couldn’t find any reliable information about sodium acetate being useful as a cleaning agent.
Right now I can almost hear you saying: “But my uncle’s girlfriend has a neighbor whose mother used this stuff to clean her whole house everyday! So what about that? Huh?!”
Well, there are at least 3 potential factors at work here. First of all, the majority of what is left over from an acid-base reaction is usually water. And while sodium acetate itself might not have many cleansing properties due to its chemistry, water does. It’s called the “universal solvent” because most compounds can be dissolved in water. This means that plain old water is itself a powerful cleaning agent.
Second, the sodium acetate can act as an abrasive that works to scrape away stubborn residues. However, you could easily get the same result by mixing water with plain table salt.
Finally, if you don’t have the exact amount of baking soda necessary to completely neutralize the vinegar you may still have a significant amount of vinegar left over in the solution.
So the next time you decide to tackle those tough stains, remember that when it comes to vinegar and baking soda, separate is typically better.
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