1. CHAPTER 19
ACIDS & BASES

2. What do you see?

3. Acid Properties Sour taste (citrus fruits) Conduct electric current
Change the color of indicators-turns litmus paper red
pH concentration < 7
React with bases to produce salt and water:
HCl + NaOH  H2O + NaCl
Some react with metals to release H2 gas:
Mg + HCl  MgCl2 + H2

4. Naming Acids Binary Acids: a. H2S hydrosulfuric acid 2. Ternary Acids:
a. H2SO4
- “IC I ATE that” sulfuric acid
b. H2SO3
-“RITEOUS” sulfurous acid

5. Base (alkaline) Properties
Bitter taste (coffee)
Feel slippery (soap)
Change the color of indicators-turns litmus paper blue
Caustic- attack the skin, cause severe burns
Conduct electric current

6. Arrhenius Acids and Bases
A compound that produces H+ in solution. Ionizes to yield a proton in an aqueous solution.
Ex: HCl (g)  H+ (aq) + Cl- (aq)
Arrhenius Base:
A compound that produces OH- in solution.
Ex: NaOH (s)  Na+ (aq) + OH- (aq)
H2O
H2O

7. Hydronium ion
The particle formed by the combination of a hydrogen ion with a water molecule.
H+ + H2O H3O+1

8. pH Scale A more convenient way to express acidity pH = -log[H3O+]
pOH = -log[OH-]
pH + pOH = 14.0

9. Find the pH and pOH of a 1x10-10 M solution of HBr.
1. HBr is an acid so we are looking at the [H+] concentration.
[H+] = 1x10-10 M
2. pH = -log[1x10-10]
pH = 10
3. pH + pOH = 14
10 + pOH = 14
pOH = 4

10. pH pH 0-7: acidic solution pH 7: neutral solution
pH 7-14: basic solution

11. Calculating pH pH = -log [H+]
Ex: A solution has a H+ concentration of 1x10-5
pH = -log [1x10-5]
pH = 5 and we have an acidic solution
Ex: A solution has a pH=8
8 = -log [H+]
[H+] = 1 x 10-8

12. Take a look at this!!!!!

14. ACIDS & BASES Titrations
CHAPTERS 19
ACIDS & BASES
Titrations

15. Indicators and Titration
Acid-Base Indicators: Compounds whose colors are sensitive to pH.
Titration: Method used to determine an unknown concentration of solution.

16. Equivalence Point
When the number of moles of hydrogen ions equals the number of moles of hydroxide ions.

17. NEUTRALIZATION OF ACIDS & BASES
If we need to neutralize an acid or a base, we use the following formula:
MaVaCb = MbVbCa
Mx=Molarity (mol/L) of the acid or base
Vx=Volume (L) of the acid or base
Cx =Coefficient (balanced eq.) of the acid or base

18. MaVaCb = MbVbCa Example:
A 25mL solution of H2SO4 is neutralized by 18mL of a 1.0M NaOH using phenolphthalein as an indicator.
What is the concentration (M) of the H2SO4?
Step 1: Write the neutralization rxn and balance
H2SO4 + 2NaOH Na2SO4 + 2H2O
Step 2: Solve for the unknown.
Ma = MbVbCa (1.0M)(0.018L)(1)
VaCb (0.025L)(2)
Ma = 0.36M

19. MOLARITY vs NORMALITY
Molarity—moles of solute contained in 1 liter of solution (moles/Liter)
Normality—moles of reactive units for each liter of solution
IN ACID-BASE REACTIONS:
CaVa = CbVb
Ex #1—H3PO (N=H+ ions so N=3)
Ex #2---Mg(OH)2 (N=OH- ions so N=2)