Acids and Bases “Tragedy is like strong acid -- it dissolves away all but the very gold of truth.” - D.H. Lawrence

Characteristics of Acids Taste _______________. Conduct __________________________ Cause _______________________ React with ________ to form ________ React with _____________ to form _____ and a ________. Produce ___ ions in water.

Characteristics of Bases Taste _____________ Slippery. Can be _______________ Produce ___________ in water. React with acids to produce _______ and a __________.

Naming Acids and Bases Acids – Compounds that dissociate in water to give H+ ions Generic acid formula: _________ H – __________ n – number If n = 1, acid is monoprotic If n = 2, acid is diprotic If n = 3, acid is triprotic X – monatomic or polyatomic ______

Naming Acids Rules for naming acids: IF: X ends in ______, name is ___________ acid. X ends in ______, name is _________ acid.

Naming Acids Try these: HF HNO3 HI H2CO3 HClO4 H2SO3

Naming Bases Bases – Compound that produces OH- ions when dissolved in water Names the same as any other ionic compound. Examples: Note: Ammonia (NH3) is a base, even though it is not a hydroxide

Hydrogen Ions and Acidity Self ionization of water: H2O ↔ H+ + OH- In a neutral solution: [H+] = [OH-] = ____________ So: [H+] [OH-] = ______________

Hydrogen Ions and Acidity In acidic solutions: [H+] > [OH-] [H+] >__________ In basic (alkaline) solutions: [H+] < [OH-] [H+] <__________

Hydrogen Ions and Acidity It’s so hard saying “a concentration of one times ten to the negative seventh molar” all the time…Is there a better way? YES! All we need is the exponent… So if the concentration of hydrogen ions is _________, the pH = __

pH What is the pH if [H+] = What is the [H+] if the pH = 1 x 10-6 M 4 9 5.5 13.5

pH pH has a range of 0 to 14 pH < 7, solution is _________ pH is measured with an indicator or pH meter.

pH of Some Common Substances

Is there a pOH? Sure! It’s pretty much the same thing. pOH = _________ Since [H+] [OH-] = 1 x 10-14 M2 pH + pOH = ____

Strong vs. Weak Acids Strong DOES NOT mean concentrated! Some acids only partially dissociate in water. E.g. Acetic acid. These are ______ acids. HC2H3O2 ‹-› H+ + C2H3O2- Acids that completely dissociate in water are _______ acids. E.g. Hydrochloric acid HCl → H+ + Cl-

Strong vs. Weak Acids Acids can be STRONG and Concentrated 12M HCl Acids can be STRONG and Dilute 0.01M HNO3 Acids can be WEAK and Concentrated 12M H2CO3 Acids can be WEAK and Dilute 0.01M HC2H3O2

How can you tell if an acid is strong? Look for the Acid Dissociation constant, __ So large Ka = _______ acid. Small Ka = _______ acid

Neutralization Reactions Acids and Bases react to form water and a salt. The products are neutral if the number of moles of H+ = moles of OH- This is referred to as the _________________. If we add a volume of a known concentration of an acid/base to a volume of an unknown concentration of base/acid, we can determine the unknown’s concentration. This process is known as _____________.

Titrations Titrations use indicator dyes to determine if the solutions have been neutralized. ___________ – Point at which the indicator changes color and the titration is stopped. ____________ and ______________ are not the same thing. However, the goal of a titration is to have the end point as close to the equivalence point as possible.

So how do we use titrations? We can find the concentration of a solution is we have a solution of known concentration. Let’s say we have neutralize 25 mL of H2SO4 solution with 18 mL of 1.0 M NaOH solution. What is the concentration of the H2SO4?

Titrations First, we need to write a balanced equation. Acid Base

Titrations Given: VA= 25 mL, MB= 1.0M, VB=18 mL Next, you can use the following relationship: Where __ is the coefficient from the reaction, __ is molarity, __ is volume, __ is the acid, and __ is the base.

Titrations