Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Fatty acid synthesis wikipedia , lookup
Matrix-assisted laser desorption/ionization wikipedia , lookup
Butyric acid wikipedia , lookup
Magnesium in biology wikipedia , lookup
Photosynthetic reaction centre wikipedia , lookup
Biochemistry wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
An Explanation of the PH Scale - Teacher Resource 1. Pure water is a poor conductor of electricity which proves it has few ions (free electrons). An ion is an atom or a group of atoms that carries a positive or a negative charge as a result of having lost or gained one or more electrons. A free electron or other subatomic-charged particle is also referred to as an ion. 2. Pure water can be used to measure the ions or pH of a substance dissolved in the water. Please note that some substances do not dissolve completely, others do. 3. An acid can be defined as any water-soluble and sour compound capable of reacting with a base to form salts that are hydrogen-containing molecules that will give up a proton to the base and accept an unshared pair of electrons from that base. 4. A base is fundamentals foundation or a main ingredient. It is the starting place and acts upon the acid. A base is the compound that reacts with the acid to form a salt because the molecules (ions) are able to take a proton from the acid and share a pair of electrons with the acid. (A salt consists of positive ions from a base and negative ions from an acid.) 5. The pH scale can be used to measure acidity or basicity of any water solution by measuring the ion concentration which is expressed as the concentration of H3O+ (hydronium ions) in powers of 10, from 10-14 to 10. (Hydronium is a hydrated hydrogen ion. A regular hydrogen ion in water is expressed as 1420.) 6. For example, a substance can measure 10-9, which is expressed as -9. By eliminating the because the scale is logarithmic, we say the pH of the substance is 9. 7. acid 0 The pH scale is shown graphically as: neutral 7 base 14 [H30+] |M 1O-7 M 8. 9. 10. 11. 10-14 M Pure water has a pH of 7. It is neutral. As the hydronium ion increases as a neutral solution, it is more acidic. The pH goes from 7 toward 0. If the pH solution falls between 7 and 14, the solution is basic. A small strip of pH paper (litmus paper) dipped in a solution will test (through the visible change of color) the pH of most substances. NOTE: In foods, acids and bases give distinctive tastes. Acids are sour (lemon juice, vinegar). Bases are salt (sodium chloride or table salt).