I've never tried this experiment, although I've seen people do a similar experiment using Coca-Cola instead of vinegar. Our teeth are mostly made of calcium phosphate. Calcium phosphate is a very hard substance, but can be dissolved in acids. It is very hard because the individual calcium atoms and phosphate molecules are very strongly attracted to each other, so they stay tightly linked together (this is very similar to the way sodium and chlorine atoms are linked together in a crystal of table salt). However, when you put calcium phosphate in acid, both the calcium atoms and phosphate molecules are more strongly attracted to the acid molecules than they are to each other, so the solid calcium phosphate dissolves and the calcium and phosphate disperse in the acid solution (This is the same thing that happens when you put table salt into a glass of hot water -- the salt crystals dissolve and the water becomes salty. The atoms in table salt are not as strongly attracted to each other as calcium and phosphate is, so you don't need acid to dissolve table salt). This happens faster if the acid is stronger (that is, more concentrated) because there are more acid molecules to pull apart the calcium and phosphate. So very concentrated acetic acid should dissolve a tooth faster than less concentrated acetic acid. I don't know exactly how fast different concentrations will work, so you'll just have to do the experiment! I would give it a couple of days, though.
When you're working with acids, you'll probably want to talk about the pH of the acid. PH measures the strength and concentration of different acids, although it's a somewhat confusing measure. Stronger acids have lower pH (pH of 1 or 2 is fairly strong), while weaker acids have pH closer to 7. Water has pH = 7 and chemicals with pH greater than 7 are bases. The other thing to remember is that the pH scale is logarithmic, which means that each increment represents a ten-fold difference. So lemon juice, which has a pH of about 2, is actually 100 times more acidic than tomato juice, which has a pH of about 4 (something with pH = 3 would be 10 times stronger than tomato juice but 10 times weaker than lemon juice). It's a little bit confusing, but I guess it made sense back in the 1900's when it was invented. A website I found says that vinegar has a pH of about 2.5; you can probably get your science teacher to help you calculate the pH of the different dilutions of vinegar you'll be making.
There is one thing you should keep in mind while doing this experiment. Vinegar (or coke, or coffee or any acidic liquid) will definitely dissolve a tooth when you put the tooth in a bowl full of vinegar. However, this doesn't mean that drinking acidic liquids (coke, coffee) or eating acidic foods (vinegar salad dressing, tomato sauce) will really damage your teeth. Your saliva has lots of chemicals that buffer acids (including sodium bicarbonate, which is basically the same as baking soda) and prevent them from damaging your body. So as long as you're making a normal amount of saliva, vinegar won't dissolve the teeth in your mouth.Hope this helps,
Tooth enamel is primarily made up of hydroxyl apatite, which is a crystalline calcium phosphate.The dentin lying beneath the enamel is primarily dahllite, or carbonate-hydroxyl apatite. These materials dissociate in acid, and therefore any time the pH of the solutions in your mouth is low, the main components of your teeth can be dissolved, leading to cavities.
Acetic acid is a weak acid that will act in just this way to dissolve the apatite materials in your teeth. If teeth were sitting in different concentrations of acetic acid, I would expect the reaction to occur in the same way, but with those teeth that are in higher concentrations reacting the fastest!
Teeth are a mixture of the minerals apatite, a calcium phosphate mineral and calcite CaCO3. Now these minerals are dissolved in acids like acetic acid. The amount of tooth material dissolved depends on the concentration of the acid. The stronger the acid, the more tooth can be dissolved per unit volume of acid added. A good experiment is to get some chicken bones and put them in solutions such as:
1. coca cola
4. Other sodas
Then leave them in over note and see what remains!!
The acid in coke is phosphoric acid. Carbonic acid H2CO3 is also involved. Acetic acid is different again. Try this experiment. Chicken bones are made up of materials not totally unlike human teeth.
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