Warm Up

A solution has a H+ ion concentration of 3.5 X 10-8 M.a. What is the pH?b. What is the [OH-]?c. What is the pOH?d. Would the litmus paper turn color?e. What color would the cabbage juice turn?

Warm Up

A solution has a H ion concentration of 3.50 X 10-8 M.a. What is the pH? 7.46 b. What is the [OH-]? 2.88 X 10-7 Mc. What is the pOH? 6.54d. Would the litmus paper turn color?e. What color would the cabbage juice turn?

Red cabbage contains a pigment Molecule called flavin that turns color in the presence of H+ and OH- ions

pH Color2 Red4 Purple6 Violet8 Blue10 Blue/Green12 Green/Yellow

 

Lab Debrief / Calculations

1. What color did the strong acids turn?2. What color did the strong bases turn?3. Were food products primarily acids or bases?4. Were cleaning products primarily acids or

bases?5. What did you notice about the bleach?6. Were there any surprises?7. What did you learn about litmus paper?

Is it a good quantitative measure of pH?

How did you do on the WS?

3 Definitions of Acids and Bases

Arrhenius Acids and Bases

Acid- compounds containing hydrogen that ionize to yield H+ ions in aqueous solutions.

Base- compounds that ionize to yield hydroxide ions in aqueous solutions.

Bronsted-Lowry Acids and Bases

Acid- hydrogen-ion donor

Base hydrogen-ion acceptor

HNO3 + H2O NO3 + H3O

Bronsted-Lowry Acids and Basesalways travel in pairs

Reactant side

Acid- hydrogen-ion donor

Base hydrogen-ion acceptor

Product side

Conjugate acid- product formed when a base accepts a H+.

Conjugate base- product formed when an acid has donated a H+.

HNO3 + H2O NO3 + H3O

Identify the following as Bronsted-Lowry acids or bases.

1. HNO3 + LiOH LiNO3 + HOH

2. 2HBr + Ca(OH)2 CaBr2 + 2HOH

Which are the conjugate acids and bases?

Lewis Acids and Bases

Where have your heard that name before??

Lewis Acids and Bases

This is a more general concept and works to include compounds that may not have H+ or OH-.

Acid- a substance that accepts a pair of electrons

Base- a substance that can donate a pair of electrons

Draw the Lewis dot structures for

NH3 and BF3

Which would be the Lewis Acid? Base??

Strong Acids and BasesStrong Acids- ionize completely in

aqueous solution.

Weak Acids – only partially ionize in solution

Strong Bases- ionize completely.

Weak Bases- partially ionize.

Let’s talk about neutralization reactions!!

Warm Up

Predict the products and balance the following reaction

KOH + H2SO4

How many grams of sulfuric acid is needed to neutralize 2.76g of potassium hydroxide.

Vocab Terms

Binary acid- contains two different elements, H and something else.

Polyprotic acid- contains two or more H+ ions.

Oxyacid- compound with H, O and a 3rd element (typically a nonmetal).

Classify the acids--

Are they binary, polyprotic or an oxyacid?

HCl

H2SO4

HNO3

H3PO4

HC2H3O2

H2CO3

Who remembers the 6 acids that you had to memorize?

Identify the following as Bronsted-Lowry acids or bases.

1. H2SO4+ Ca(OH)2 HOH + CaSO4

2. 2HF + Mg(OH)2 CaF2 + 2HOH

Which are the conjugate acids and bases?

How did you do on pH calculations?

How about the neutralization problems?

Quiz

Go to the titration ppt.