intro to Chemistry
Signature Assignment: |
Foam and fizzing
Chemistry beind the foaming and fizz
Equation (chemical reaction when acetic acid is added with sodium bicarbonate):
NaHCO3 (S)+ CH3COOH (l)----->CH3COONa (aq) + H2O (l) + CO2 (g)
Sodium + Acetic acid = Sodium + Water + Carbon
bicarbonate acetate dioxide
bicarbonate acetate dioxide
Why does this happen? |
As talked about in my chemistry class, the definition of base is, a compound that wants to donate electrons. In the case of this experiment the base is sodium bicarbonate. An acid is a compound that wants to accept electrons or in other words get rid of a positively charged hydrogen atom, in this case that's vinegar or dilute acetic acid. As you can see it's the perfect situation because the acid is ready to get rid of it's proton and the base is there to receive it. I added water because it serves as a host in which the acid and base can break apart easier.
In the water the sodium bicarbonate breaks apart into positively charged sodium ion (Na+) and negative bicarbonate ion (HCO3-). The acetic acid breaks up into a positively charged hydrogen (H+) and negatively charged acetate (C2H3O2-). When mixed in water, the hydrogen atom which was in the acetic acid gets together with the hydrogen and oxygen atoms, that had been in the sodium bicarbonate, and it forms a molecule of water (H2O). The acetate ion gets together with the sodium atom and forms sodium acetate (CH3COONa).
The carbon dioxide molecule (CO2) is now free from it's previous bonds and it comes out the soultion as bubbles. This is because they are being created very quicly so the carbon comes out as a gas. The laudry detergent used in this experiment made the bubbles last longer and created foam. When laudry detergent is added to water it changes the surface tension of the water. Normal water has a high surface tension which is the force holding the molecules of a liquid together. When you add the detergent, the molecules increase the distance between water molecules and reduce the ability of interaction between the molecules. It basically lowers the surface tension and bubbles form. In the end, the bubbles and foam that can be seen are filled with carbon dioxide gas (CO2) that was released because of an acid/base reaction.
In the water the sodium bicarbonate breaks apart into positively charged sodium ion (Na+) and negative bicarbonate ion (HCO3-). The acetic acid breaks up into a positively charged hydrogen (H+) and negatively charged acetate (C2H3O2-). When mixed in water, the hydrogen atom which was in the acetic acid gets together with the hydrogen and oxygen atoms, that had been in the sodium bicarbonate, and it forms a molecule of water (H2O). The acetate ion gets together with the sodium atom and forms sodium acetate (CH3COONa).
The carbon dioxide molecule (CO2) is now free from it's previous bonds and it comes out the soultion as bubbles. This is because they are being created very quicly so the carbon comes out as a gas. The laudry detergent used in this experiment made the bubbles last longer and created foam. When laudry detergent is added to water it changes the surface tension of the water. Normal water has a high surface tension which is the force holding the molecules of a liquid together. When you add the detergent, the molecules increase the distance between water molecules and reduce the ability of interaction between the molecules. It basically lowers the surface tension and bubbles form. In the end, the bubbles and foam that can be seen are filled with carbon dioxide gas (CO2) that was released because of an acid/base reaction.
refelection:
exploring Acid-base reactions
In my old school I was part of the science research class and that meant we had to come up with experiments to teach children that they would find intersting and be intrigued . Back then, having not taken a chemistry class, I just choose a project were there was a volcano like eruption. While learning about how molecules interact, what can be formed and why it happens I thought back to this experiment. I knew that bubbles came out but I didn't know why and how that resulted from ingredients such as backing soda and vingear. I looked back through the notes for this sememster and went over solubility rules and more. This class has given me information to be able to solve problems that I couldn't come up with an answer to before. What was talked about in this experiment can be connected to other life situations and provides insight into why it is that there is foam, bubbles or any other reaction ocurred. This kind of information could help those who are not skilled in the kitchen understand why there's foam everywhere when they were trying to come up with a recipe involving backing soda and vinegar.