1. October 3, 2011

2. What is an acid? Acids are compounds that accept electrons from other chemicals known as bases. Many acids contain hydrogen. Acids taste sour, conduct electricity, and often react with metals to release hydrogen gas. We measure the strength of acids with the pH scale. Very strong acids have a pH of 0. Weak acids have a pH of 6.

3. What is a base? A base is a compound that donates electrons to an acid. Bases taste bitter, are slippery, and conduct electricity. We measure the strength of bases with the pH scale. Very strong acids have a pH of 14. Weak bases have a pH of 8.

4. The pH scale Indicators like litmus paper and phenolphthalein can identify chemicals as acids or bases

5. Acid-Base Reactions When acids and bases react, they neutralize each other. The products are generally salt and water. Energy is often released as heat. Exothermic reactions – heat is produced or released during the reaction

6. Law of Conservation of Matter Matter can be neither created nor destroyed. The mass of the reactants of a reaction must be equal to the mass of the products of a reaction. 2g H 2 + 16g O 2 -> 18g H 2 O The numbers of atoms of each element in the reactants must be equal to the numbers of atoms of each element in the products. 2 H 2 + O 2 -> 2H 2 O

7. Law of Conservation of Matter The numbers of atoms of each element in the reactants must be equal to the numbers of atoms of each element in the products. 2 H 2 + O 2 -> 2H 2 O Atoms in ReactantsAtoms in Products HOHO