Acids can take many forms, so the definition may be broader than you expect. An encompassing, brief definition could be said that acids; Are any substance that reacts to a base, has a PH of 7.0, or less, and surprisingly can be a gas, liquid, or solid. It "burns through things", because said reaction above is corrosive by it's nature. Hope this helps.
For chemistry, acid has a very specific definition that has to do with Ph (percentage of hydronium ions) a Ph 7 is neutral. Ph 1 is a very strong acid (like the stomach acid) and Ph 14 is a strong base (like most laundry detergents). Pure water is neutral but water that cones out of the faucet is slightly acidic because it contains dissolved CO2. Neither an acid or a base burn through anything but they do react strongly with most hydrocarbon based compounds. All animals are hydrocarbon based compounds which makes it easier for kidnappers to dissolve the bodies of their victims and dump the remaining slush in the sewer. The Ph must also be used to balance the base/acid in aquariums to keep the fish alive so people will add an acid or base and use Ph paper to test the water. That's just the basics, hope you find it informative.
11 months ago
Last edited at 2:54PM on 4/5/2013
Many, many compounds, both organic and inorganic dissolve in water to become acids. They release a predominance of hydrogen ions in the water, producing pH as low as zero. Which is VERY powerful acid indeed. Organic acids contain the group COOH (carboxyl radical) which is weak as far as acidity goes. The strongest acids are sulfuric (H2S04) and Nitric (HNO3) and a mixture of those will dissolve GOLD!!! Hydrofluoric acid (HF) is nasty stuff and will attack almost anything, including glass!!! Phosphoric acid, with THREE hydrogens is so weak it is used to flavor Cola drinks! Most of your organic acids are weak enough that all they dissolve is the gunk around your teeth....