Drill  Compare and contrast acids and bases.

Objective:  SWBAT: Explore acids and bases in order to determine the pH of different household products.

SAT Enrichment  Define Corrosive:  of a substance, especially a strong acid; capable of destroying or eating away by chemical action

Hydrogen Ions and Acidity Why is Hydrogen soooo important??

Hydrogen Ions and Acidity To test a diagnosis of diabetic coma, a doctor orders several tests, including the acidity of the patient’s blood. Results from this test will be expressed in units of pH. You will learn how the pH scale is used to indicate the acidity of a solution and why the pH scale is used.

Hydrogen Ions from Water  The reaction in which water molecules produce ions is called the self-ionization of water.

Hydrogen Ions from Water  In the self-ionization of water, a proton (hydrogen ion) transfers from one water molecule to another water molecule.

Ion Product Constant for Water  For aqueous solutions, the product of the hydrogen-ion concentration and the hydroxide-ion concentration equals 1.0   Any aqueous solution in which [H + ] and [OH - ] are equal is described as a neutral solution.

Ion Product Constant for Water  The product of the concentrations of the hydrogen ions and hydroxide ions in water is called the ion-product constant for water (K w ).

Ion Product Constant for Water  An acidic solution is one in which [H + ] is greater than [OH - ].

Ion Product Constant for Water  Unrefined hydrochloric acid, commonly called muriatic acid, is used to clean stone buildings and swimming pools.

Ion Product Constant for Water  A basic solution is one in which [H + ] is less than [OH  ]. Basic solutions are also known as alkaline solutions.

Ion Product Constant for Water  Sodium hydroxide, or lye, is commonly used as a drain cleaner.

The pH Concept  The pH of a solution is the negative logarithm of the hydrogen-ion concentration.

Calculating pH A solution in which [H+] is greater than 1  10–7 M has a pH less than 7.0 and is acidic. The pH of pure water or a neutral aqueous solution is 7.0. A solution with a pH greater than 7 is basic and has a [H+] of less than 1  10–7 M.

The pH Concept

Calculating pOH

pH and Significant Figures

Measuring pH  An indicator is a valuable tool for measuring pH because its acid form and base form have different colors in solution. Phenolphthalein changes from colorless to pink at pH 7–9.

Review 1. The [OH - ] for four solutions is given below. Which one of the solution is basic? a.1.0 x M b.1.0 x M c.1.0 x M d.1.0 x M

Review 2. What is the pH of a solution with a hydrogen-ion concentration of 8.5 x M? a b.8.50 c.5.50 d.1.07

Calculating pH  Complete pH Worksheet  Working with pH

Color Ranges

Universal Indicators

pH Meters

Measuring pH  Complete class work activity:  You have 15 min  Complete pre-Lab questions  Gather your data  Report back to your seat

Online stimulation  Make sure your screen looks like this: If your screen does not look like this raise your hand! Timer 15 min

Sharing Data  Each group will share report their data on the board.  Analysis Questions  Each student will have 10 mins to complete their analysis questions individually.  Place the paper in the bin when finished. Timer 10 min

Summary 1.Did we accomplish the objective? Explain. 2.Explain the different types of test that may be done in order to determine if a substance is an acid or base. 3.Explain if the method use during class today was useful in determining if the household items were acids or bases. 4.What did you notice about most acids? Most bases? 5.Explain what may happen to the pH of an acid when water is added? A Base?

Homework  Determination of pH worksheet.  Exit ticket:  Acids and Bases  Place Exit ticket in the bin when finished.