How can you tell an acid from base?
Answer (new):There are many ways to test a solution. Some of the most popular are:
- Litmus paper is paper treated with litmus powder. It turns red in pH<4.5 (acidic) and blue in pH>8.3 (basic.)
- Pheophthalein is a colourless liquid that turns pink in basic solution. The more concentrated the base, the deeper the pink.
- Universal indicator is a solution that is added to a solution. At pH<3 it is red and it goes through the colour spectrum until it hits violet when in a solution of pH>11
- Hydrion papers are papers treated with a universal indicator that are marketed commercially.
•An acid is a proton donor
•A base is a proton receiver
HCl + OH- >> Cl- + HOH
•A Lewis acid receives a pair of electrons
•A Lewis base donates a pair of electrons
The currently accepted theory is the Lewis acid-base theory A Lewis base is an electron donor and a Lewis acid is a electron acceptor. Whether a compound is acid or base may not be obvious at first and difficult to work out. There are rules for working this out but you probably dont have to know them Generally, all you would probably have to know is that an acid is a proton [H+] donor and…
If you have an acid of unknown strength, you add Universal Indicator & add drops of a base. Count the drops of the base until the solution turns green (neutral) This should tell you how strong the acid is. This can also be done the other way (with a base of unknown strength & adding an acid) Does that make sense?