Acids & Bases

Other scales that are logarithmic? The Richter Scale! Hydrogen donors The pH Scale The scale is inversely proportional to the number of hydronium ions present in the solution. The more hydrogen ions, the lower the pH Scale is BASE 10!!!! pH of 2 is 100 times more acidic than a pH of 4… NOT twice! The pH scale is based on the concentration of Hydrogen ions within a solution. (called hydronium) Other scales that are logarithmic? The Richter Scale! Hydrogen acceptors

Acids are hydrogen donors, Bases are Hydrogen acceptors. Thus, acids often have a chemical formula that starts with “H”, while bases often have a chemical formula that ends with “OH”. OH- is called a “hydroxide ion” H+ is a hydrogen ion (or just a proton)

Some strong Acids HCl HBr H2SO4 HNO3 (Hydrochloric Acid) (Hydrobromic Acid) H2SO4 (Sulfuric Acid) HNO3 (Nitric Acid)

Some Strong Bases NaOH KOH Ca(OH)2 (Sodium Hydroxide) (Potassium Hydroxide) Ca(OH)2 (Calcium Hydroxide)

Ph scale is used to measure the acidity or alkalinity of a solution. pH scale is defined as the negative logarithm of the hydrogen ion concentration in a solution. pH scale therefore increases and decreases by powers of 10.

Buffers Buffers keep the pH of a system from fluctuating very much. Without buffers, pH of a system can fluctuate greatly as well as VERY quickly!

Buffers The internal pH of most living cells is very close to 7, and blood pH is 7.40 You cannot survive more than a few minutes if blood pH fluctuates very far.(+ or - .05) The most important buffering system for humans is the carbonic acid-bicarbonate system present in the blood. Most buffering systems are weak acid-base pairs.

Threats to water quality Contamination of rivers, lakes, seas, and aquifers is a massive problem. Just a slight decrease in water quality can have DRASTIC effects on living organisms. Water pH Toxic chemicals Waste runoff

pH change can kill fish

Be able to complete the following: An ________ is a substance with a pH between 0 - 7. They are also known as hydrogen _________. Usually their chemical formula begins with ______. A ______ is a substance with a pH between 7 - 14. They are also known as hydrogen ________. Usually their chemical formula ends with ______, a compound which is also known as __________.