pH

For what values is a solution acidic, basic. neutral?

pH = -Log[H⁺]

thedegree of acidity of a solution

pH values:

<7 = acid

7 = neutral

>7 = basic

pOH

For what values is a solution acidic, basic, neutral?

pOH = -Log[OH^-]

the degree pf basicity of a solution

pOH values:

 <7 = basic

7 = neutral

>7 = acid

1. How are pH and pOH of a solution related?

2. How are the concentrations of [H⁺] and [OH^-] related in a solution?

1. The sum of the two values = 14

pH + pOH = 14

2. The product of the concentrations = 1 x 10^-14

[H+][OH-] = 1 x 10^-14

Match these pH values (2,7,12) to these substances:

(distilled water, lye, stomach juice)

stomach juice = 2

distilled water = 7

lye (NaOH) = 12

For a solution with a pH of 3 find

1. pOH

2. [H+]

3. [OH-]

1.pH + pOH = 12 pOH = 11

2. pH = -log[H+]

[H+] = 1 x 10^-3

3. [H+][OH-] = 1 x 10^-14

[OH-] = 1x10^-11

1. Solubility product constant - K_sp

2. Write the solubilty product expression for

AgCl ↔ Ag⁺ + Cl^-

1. Am equilibrium exist in a saturated solution between dissolved and undissolved solute. "K_sp" is the equilibrium constant for this reaction

2. Ksp = [Ag+][Cl-]

In a saturated solution of BaSo₄

[Ba²⁺] = 2x10^-5

find K_sp

Each molecule of BaSO₄ that ionizes produces equal concentrations of ions; therefore:

[Ba⁺²] = [SO₄^-2]

K_sp = [Ba⁺²][SO₄^-2]

= [2x10^-5][2x10^-5] = 4x10^-10

1. Common ion effect

2. NaCl ↔ Cl^-

What happens when Cl^- is added to this system at equilibrium?

1. When an ionized reaction is at equilibrium and some additional ion is added, the reverse reaction reate increases to consume the added ion.

2. Accordind to the common ion effect- the reverse reaction will speed uo, consuming Na⁺ and Cl^-, and more NaCl will be formed

Six common characteristics of...

Acids

Form H₂O solutions

conduct electricity

react with active metals

turm blue litmus red

neutralize base

sour taste

Seven common characteristics of...

Bases

Form H₂O solutions

conduct electricity

turn red litmus blue

feel slippery

caustic

neutralize acids

base + fats form soap

nitric acid HNO₃

hydrochloric HCL

sulfuric H₂SO₄

hydriodic Hl

hydrobromic HBr

perchloric HCLO₄

hydrofluoric HF

acetic CH₃CO₂H

carbonic H₂CO₃

and most others...

oxalic

phosphoric

sulfurous

hydroxides of:

potassium

sodium

barium

strontium

calcium

(KOH, NaOH, ...)

 H₃O⁺ ion found in water solutions of acids.

water molecule with proton attached

Neutralization reaction

Write equation for hydrochloirc acid and sodium hydroxide

acid + base → salt + water

HCl + NaOH → NaCl + H₂O

An acid yields protons in solution

(H+ ions)

A base yields hydroxide ions in solution

(OH- ions) 

An acid is a proton donor

A base is a proton acceptor

An acid is an electron pair acceptor

A base is an electro pair donor

1. Conjugate base - write conjugate base of HCl

2. Conjugate acid - write conjugate acid of I-

1. When a Bronsted acid donates a proton it becomes its conjugate base (Conjugate base of HCl is Cl-)

2. When a Bronsted base accepts a proton it becomes its conjugate acid (Conjugate acid of I- is HI)

Indicator

List 4 examples

A substance which changes color along the pH scale

(Litmus, phenolphthalein, methyl orange, bromthymol blue)

1. Titration

2. Endpoint

1. A process of finding the unknown concentration of a solution by allowing it to react with another solutionof know volume and concentration

2. The point during a titration at which the acid reacts completely with the base. The indicator changes color.

M_A x V_A = M_B x V_B

molarity = M

volume = V

acid = A

base = B

2M x 5L = 10M x V_B

1L = volume of base

1. Buffer solutions

2. Electrolysis

1. Equilibrium which resist changes in pH upon the introduction of acids or bases (due to the common ion effect).

(example: a weal acid (acetic acid) and its salt (sodium acetate))

2. The passage of a direct electric current through an ionic solution, producing chemical changes at the elcetrodes