Baking soda and vinegar produce three things: carbon dioxide gas, water, and sodium acetate, a mild salt that stays dissolved in the leftover liquid.1Lifehacker. Baking Soda and Vinegar Are Good for Cleaning, Just Not Together The foaming is just the gas escaping, and almost everything else ends up as a weak, salty liquid. Because the acid and the base cancel each other out, the mixture is weaker at most jobs than either ingredient alone.
How the Fizz Happens in Two Quick Steps
Baking soda is sodium bicarbonate, a base, and vinegar is water with acetic acid in it.2NC State News. The Difference Between Baking Soda and Baking Powder When they meet, the acetic acid and the sodium bicarbonate trade parts. That swap forms sodium acetate and carbonic acid.3ThoughtCo. Equation for the Reaction Between Baking Soda and Vinegar Sodium acetate is a salt, the same family of compound as table salt but a different one.
The second step is where the gas appears. Carbonic acid is unstable and breaks down almost immediately into water and carbon dioxide.4ThoughtCo. Equation for the Reaction Between Baking Soda and Vinegar So the bubbles come from this second step, not from the baking soda simply dissolving. Overall, each unit of baking soda that reacts makes one unit each of carbon dioxide, water, and dissolved sodium acetate.5ThoughtCo. Equation for the Reaction Between Baking Soda and Vinegar
The foam itself is not a new substance. It is liquid wrapped around bubbles of carbon dioxide, the same gas we breathe out. When the bubbles stop, the gas has simply drifted into the air, and nothing in the foam is toxic at kitchen amounts.
The carbon in that gas comes from the baking soda, not the vinegar. The sodium ends up in the dissolved salt, and the vinegar’s acetate part joins it there, so both ingredients contribute to the leftover liquid.
How Much Gas You Get Depends on the Ratio
With 70 mL of vinegar, about a third of a cup, 10 grams of baking soda produced the most gas and 1.25 grams the least.6ojs.library.ubc.ca. Bubbling Baking Soda The pattern holds only up to a point. Once the vinegar’s acid is used up, extra baking soda just sits at the bottom unreacted.
The two ingredients react in a fixed proportion, so a certain amount of one can use up only a certain amount of the other. If there is more vinegar than needed, all the baking soda reacts and the leftover liquid still smells sharp. If there is more baking soda than needed, the acid is gone first and powder is left over. Adding more of the ingredient that ran out restarts the fizz, which shows the first one was the limit.
For the biggest volcano eruption, add baking soda in stages and stop when the fizz no longer comes. Fresh baking soda reacts more vigorously than an old opened box, and warm vinegar tends to react faster than cold.
Vinegar strength varies too. White vinegar is usually sold as about 5 to 6 percent acetic acid.7ChemRxiv. Determining the Acetic Acid Concentration in White Vinegar: An At-Home Undergraduate Chemistry Experiment During the COVID-19 Pandemic Yet one home test found a bottle labelled 6 percent was actually about 19 percent stronger than labelled.8ChemRxiv. Determining the Acetic Acid Concentration in White Vinegar: An At-Home Undergraduate Chemistry Experiment During the COVID-19 Pandemic So two bottles of vinegar can give noticeably different amounts of fizz.
A stronger bottle can use up more baking soda before it runs out. For a fair comparison, such as a science fair test, use the same bottle each time, and don’t treat the percent on the label as exact.
What Sodium Acetate Is and Where Else You Meet It
Sodium acetate is a food ingredient. It gives salt-and-vinegar chips their tangy flavor without wet vinegar.9PubMed Central. What Is Produced When Baking Soda Reacts With Vinegar? Foods use it as a flavoring, as a preservative that slows bacteria, and as a buffer that keeps acidity steady.10Periodical by Knowde. Sodium Acetate in Food & Beverage Products So the liquid left in your cup is a mild, slightly salty solution, safe to pour down the sink.
Whether it is sour or soapy depends on the amounts. When the acid and base are well matched, the liquid ends up close to neutral. If vinegar was in excess, it stays mildly acidic and smells like vinegar. If baking soda was in excess, it is slightly basic and can feel a little slippery. At kitchen amounts it is too mild to harm skin, though rinsing is sensible if it gets in your eyes.
Sodium acetate also makes hand warmers. A concentrated, carefully cooled solution can hold more dissolved salt than normal.11Department of Chemistry & Chemical Biology | Rutgers, The State University of New Jersey. Crystallization from a Supersaturated Solution Dropping in a single crystal makes it suddenly crystallize,12Department of Chemistry, University of Washington. Supersaturation of Sodium Acetate and the solid that forms gives off heat and feels warm to the touch.13Department of Chemistry & Chemical Biology | Rutgers, The State University of New Jersey. Crystallization from a Supersaturated Solution This is how reusable click-type hand warmers work.
You can make this “hot ice” at home, but the leftover from a quick kitchen mix is a weak solution, so you have to boil off a lot of water to concentrate it. The concentrated liquid is then cooled without bumping or stirring it, so it stays liquid even though it holds extra dissolved salt. Touching it with a tiny crystal of the salt sets off fast crystal growth that builds into a solid tower you can watch. Boiling is involved, so an adult should do or supervise that step.
Why the Mixture Turns Cold
The reaction draws heat in from its surroundings as it proceeds.14Go Science Girls. Does Baking Soda Change the Temperature of Water Science Project In one home test, baking soda and vinegar alone dropped the temperature by 9 °F, and the jar felt cold.15Frugal Fun For Boys and Girls. Chilly Chemical Reactions! {Endothermic Reactions} With dish soap added, the drop was 7 °F.16Frugal Fun For Boys and Girls. Chilly Chemical Reactions! {Endothermic Reactions}
You can see this yourself. Measure the vinegar’s temperature with a kitchen thermometer, then stir in the baking soda and read it again while it fizzes. Larger amounts of both ingredients give a bigger drop, because more reaction pulls in more heat. The cold lasts only until the fizzing ends, after which the mixture slowly warms back to room temperature.
Does It Clean Drains or Surfaces
The acid and base react with each other, not with the dirt.17Lifehacker. Baking Soda and Vinegar Are Good for Cleaning, Just Not Together So the mixture is usually no better at cleaning than water.18Lifehacker. Baking Soda and Vinegar Are Good for Cleaning, Just Not Together Vinegar’s acid is what dissolves mineral deposits, and baking soda’s base is what loosens grease, but mixing them cancels both. What is left is mostly salty water, and the cleaning power you wanted has been spent making gas.
Each works well on its own. Vinegar dissolves limescale on kettles and showerheads, and a baking soda paste scrubs ovens and pans. If you want both effects, use them one after the other, rinsing between.
Drains are the popular use. In an open drain the gas escapes up and out, so it doesn’t build pressure against a clog.19IPP Solutions. Why Does a Plumber Expert Warn Against Using Vinegar and Baking Soda on Drains Drain-product makers say the bubbling helps loosen material,20Liquid-Plumr. How to Clean Drains with Baking Soda and Vinegar but a clog of hair and soap scum is held together physically, and the mixture has little power to dissolve it. At best it helps a minor slow drain, especially when followed by hot water, which may help a light, greasy clog but is no guarantee for a real blockage.
Better options exist. Pour boiling water for grease, except into plastic pipes that may soften. Use a plunger or a drain snake to move a clog physically, and clear hair from the stopper. For repeated blockages, call a plumber.
How the Same Reaction Makes Cakes Rise
In batter, baking soda and an acid release carbon dioxide that makes food expand and turn fluffy.21K-State Extension Johnson County. 3 Key Chemical Leavening Agents in Baking As it bakes, the gas expands the air trapped in the dough.22Bob’s Red Mill Natural Foods. What Does Baking Soda Do? Baking soda reacts almost immediately with acid,23NC State News. The Difference Between Baking Soda and Baking Powder so the bubbles begin in the bowl, not the oven. If batter sits too long, much of the gas escapes before baking and the cake comes out flatter. Recipes using baking soda alone should go into the oven soon after mixing, with the wet and dry ingredients combined last.
Recipes with an acidic ingredient like buttermilk usually call for baking soda.24Office for Science and Society. What’s the Difference Between Baking Soda and Baking Powder? Yogurt, lemon juice, and vinegar work too. Such recipes are balanced so the soda is mostly used up. A recipe without an acidic ingredient usually calls for baking powder instead.
Baking powder is baking soda already mixed with dry powdered acids.25Office for Science and Society. What’s the Difference Between Baking Soda and Baking Powder? One acid reacts once the powder gets wet.26NC State News. The Difference Between Baking Soda and Baking Powder A second acid waits until the batter is both wet and hot in the oven.27NC State News. The Difference Between Baking Soda and Baking Powder So the batter keeps rising longer and comes out fluffier.
Baking powder can stand in for baking soda, but you need more of it because it is only partly baking soda. The swap can change flavor and texture, so it works best in simple recipes. Going the other way fails when there is no acid: nothing reacts, and the unreacted soda tastes soapy and bitter. Too much baking soda, even with acid, can leave the same taste because extra soda is left over. To test baking soda for freshness, put a spoonful in vinegar. It should fizz hard.
When the Gas Can Become a Hazard
The danger comes only when the gas is trapped. In a sealed container the reaction can build real pressure.28IPP Solutions. Why Does a Plumber Expert Warn Against Using Vinegar and Baking Soda on Drains A corked bottle rocket launches when that pressure shoots out the cork.29ARM & HAMMER. 7 Baking Soda & Vinegar STEM Activities & Experiments Glass is the worst case because it can shatter into sharp pieces, so never seal this reaction in a glass jar. Carbon dioxide puts out flames, so the gas itself won’t catch fire.30PubMed. Joseph Black, carbon dioxide, latent heat, and the beginnings of the discovery of the respiratory gases
For rocket and volcano play, use plastic bottles rather than glass, and launch outdoors in open space. Point the bottle away from faces and other people, and stand back after it is sealed. Wear eye protection, because vinegar stings and a splash can happen. Rinse any splashes off skin or eyes with plenty of water.
Dish soap changes how a volcano looks. It traps gas in bubbles, making thick foam and a slower lava flow rather than a splash.