It depends. If you just want to see the reaction happen, then a few teaspoons of each of vinegar and baking soda will be more than enough to view the reaction.

If you want to be very exact and you want both your vinegar and baking soda to react completely with no leftover starting materials, then you would need an equal number of molecules of vinegar and baking soda for this reaction. An equal number of molecules, unfortunately, doesn’t translate to equal volumes that you can measure out with your measuring cup. This is because vinegar and baking soda have different size molecules and also different densities.

In order to calculate this, you have to know a few things which you probably haven’t learned yet in science class including a few concepts called: balancing chemical equations, dimensional analysis and molecular mass. Most students learn these concepts in high school.

The result of these calculations is that you need about 1.5 teaspoons of vinegar for every teaspoon of baking soda. I will put the math in the answer that is posted on the website in case you want to look at it, but don’t worry if you don’t understand it yet. You’ll learn these concepts later. Have fun making your reaction!

FOR HIGH SCHOOL STUDENTS :

It depends. If you just want to see the reaction happen, then a few teaspoons of each of vinegar and baking soda will be more than enough to view the reaction.

If you want to be very exact and you want both your vinegar and baking soda to react completely with no leftover starting materials, then you would need an equal number of molecules of vinegar and baking soda for this reaction. An equal number of molecules, unfortunately, doesn’t translate to equal volumes that you can measure out with your measuring cup. This is because vinegar and baking soda have different size molecules and also different densities.

In order to calculate this, you have to know about a few concepts called: balancing chemical equations, dimensional analysis and molecular mass. Most students learn these concepts in high school.

The result of these calculations is that you need about 1.5 teaspoons of vinegar for every 1 teaspoon of baking soda. The math is attached for advanced students to show how the calculation is done.