what makes bicarb and citric acid react ?

Answer 1

The flying spaghetti monster forces them to react. It MAKES them react.

Just kidding. I think.

This reaction is actually an acid-acid equilibrium between citric acid/sodium bicarbonate (on the left below) and carbonic acid/sodium citrate (in the middle), followed by a very fast decay of carbonic acid into water and carbon dioxide (on the right). Let's look at the complete chemical equation, using "A" to stand for the citrate anion:

NaHCO3 + HA <---> H2CO3 + HA ---> H2O + CO2 + NaA

One thing that "makes" this reaction go is the fact that citrate is a stronger base than bicarbonate is. This means that the OH bond in carbonic acid that forms as a result of HCO3- yanking a proton off of citric acid is stronger than the one that exists in citric acid. This makes the reaction enthalpy favored, and drives it.

A second thing that "makes" the reaction go is the fact that you are reacting two molecules and eventually producing three, one of which is a gas. This makes the reaction favored by entropy, and drives it.

This thing is also being driven by what is called "Le Chatelier's principle" (pronounced "Luh shot-lee-ay's principle"). One of the products (CO2) is a gas, and the gas leaves the reaction mixture by going off into the atmosphere. Removing a molecule from the right side makes more molecules on the left side react. This also drives the reaction from left to right, as written.

Answer 2

except for the word chemicals, what nathan said made little to no sense. the reaction between bicarbonate and citric acid is an acid-base reaction. molecules with hyrdrogens all have the potential to donate these hydrogens in the form of protons, some being strong than others. we can measure exactly how strong the desire to donate these protons, known as acidity, is with a number called its pKa. you can use the pKa of two molecules can be used to determine whether or not the two will react in an acid-base reaction.

the pKa of citric acid is approixmatley 3, which is weakly acidic. when it is added to a mixture with bicarbonate, the bicarb acts as a base and accepts a proton to form carbonic acid. carbonic acid has a pKa of about 6.5. since citric acid is a strong acid than carbonic acid, the reaction favors pushing towards the weaker acid. you can set up an equilibrium that looks like:

citric acid + (sodium) bicarbonate <------> (sodium) citrate + carbonic acid

(note: lower pKa's are more acidic)

Answer 3

The reaction between a caustic and an acid.

It's all a matter of PH. All chemicals have a PH from 1-14. Water is neutral @ 7.6. Anything above 7.6 is caustic. Anything below acidic. When mixed, chemicals attempt to create an equilibrium. The further apart the chemicals are on the scale, the more violent the reaction.

Answer 4

Salt

Answer 5

NaHCO3+ H(citrate) ===> Na+ + citrate- + CO2(g) + H2O

Answer 6

each other:)