ACIDS, BASES, & BUFFERS

In water, the concentration of H+ is equal to the concentration of OH-. By definition, pure water is ______________________ A solution is ACIDIC if the _______________ A solution is BASIC if the ________________   [ H+] = [OH-] NEUTRAL [ H+] > [OH-] [ H+] < [OH-]

pH SCALE [ H+] pH is the concentration of ____ expressed as a logarithm. Every change in the pH scale of one unit is a change in ______ times the concentration of H+. 10 See p.3-6 Fluids & Electrolytes CD

See p.11 Fluids & Electrolytes CD

pH paper animation http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks3/science/acids/index.htm

ACIDS pH of 0 to 6.9 Contribute H+ ions into a solution Turn litmus paper RED Conduct ELECTRICITY Produce H+ gas (with some metals) Are CORROSIVE See p.7-9 Fluids & Electrolytes CD

BASES pH of 7.1 to 14 Remove H+ ions from a solution The hydroxide [OH-] group attaches to the hydrogen and water is formed. Turns litmus paper BLUE Conduct ELECTRICITY Are Slippery Are CAUSTIC BASES See p.10 Fluids & Electrolytes CD

acids release H+ ions into the solution bases remove H+ ions from the solution H2O H+ and OH-

Why is it Important to Maintain pH? The pH of almost all living systems is between pH ________. Maintaining the proper pH then is vital living systems. Living organisms maintain a proper pH balance by using the homeostatic control of buffers. 6 - 8 See p.13-15 Fluids & Electrolytes CD