The wonderful world of Acids & Bases
Characteristics of Acids
- Tastes sour
- React with metals & carbonates
- Turn blue litmus paper red
- Produce Hydrogen ions (+) when mixed with water
- Fall anywhere between 0 - 6.9 on the pH scale
Characteristics of Bases
- Tastes bitter
- Do not react with metals or carbonates
- Turn red litmus paper Blue
- Produce Hydroxide ions (-) when mixed with water
- Fall anywhere between 7.1 - 14 on the pH scale
It is important to understand that when an acid or base reacts with water different things happen. The pH scale literally means potential of Hydrogen so the acids have a much higher potential then the bases. It is the amount of Hydrogen ions that make acids acids and bases bases.
The strength of acids and bases depend on where it falls on the pH scale. Hydrochloric acid is very strong, meaning it has a pH closer to 0. Citric acid on the other hand is quite weak (because we actually ingest this acid) and it is closer to 7 on the pH scale. The same goes for bases. Drain cleaner is a very strong base that is closer to 14 while ammonia will irritate your hands but it is a relatively weak base with a pH closer to 7.
Below is a diagram of a pH scale. Remember that the pH scale is actually logarithm (1 x 10 - x) where an acid with the pH of 1 will have .1 hydrogen atoms while a base with a pH of 13 will have .0000000000001 hydrogen atoms.
When a solution has a pH of 7 it is said to be Neutral. Distilled water has a pH of 7. It is interesting when you mix an acid together with a base of the same strength they will neutralize each other much like the sodium hydroxide and hydrochloric acid demonstration I did in class.
- Video of an acid/base neutralization reaction
The video explains, as I did in class, that the byproducts of an acid and base neutralization are water and a salt. Salt is a generic term used in chemistry to refer to an ionic compound that is made from a neutralization of an acid and base.
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| Photo courtesy of www.wikipedia.org |
- Tastes sour
- React with metals & carbonates
- Turn blue litmus paper red
- Produce Hydrogen ions (+) when mixed with water
- Fall anywhere between 0 - 6.9 on the pH scale
 |
| Photo courtesy of www.apartmenttherapy.com |
Characteristics of Bases
- Tastes bitter
- Do not react with metals or carbonates
- Turn red litmus paper Blue
- Produce Hydroxide ions (-) when mixed with water
- Fall anywhere between 7.1 - 14 on the pH scale
It is important to understand that when an acid or base reacts with water different things happen. The pH scale literally means potential of Hydrogen so the acids have a much higher potential then the bases. It is the amount of Hydrogen ions that make acids acids and bases bases.
The strength of acids and bases depend on where it falls on the pH scale. Hydrochloric acid is very strong, meaning it has a pH closer to 0. Citric acid on the other hand is quite weak (because we actually ingest this acid) and it is closer to 7 on the pH scale. The same goes for bases. Drain cleaner is a very strong base that is closer to 14 while ammonia will irritate your hands but it is a relatively weak base with a pH closer to 7.
Below is a diagram of a pH scale. Remember that the pH scale is actually logarithm (1 x 10 - x) where an acid with the pH of 1 will have .1 hydrogen atoms while a base with a pH of 13 will have .0000000000001 hydrogen atoms.
 |
| Image courtesy of http://richardanderson.me.uk |
- Video of an acid/base neutralization reaction
The video explains, as I did in class, that the byproducts of an acid and base neutralization are water and a salt. Salt is a generic term used in chemistry to refer to an ionic compound that is made from a neutralization of an acid and base.
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