Acids and Bases

What is a bronsted-lowry acid

An acid that DONATES a proton (H+)

What is the equation for a bronsted-lowry acid

HA (aq) + H2O (l) → A- (aq) + H3O+ (aq)

What ia bronsted-lowry base

A base ACCEPTS a proton (H+)

What is the equation for a bronsted-lowry base

B (aq) + H2O (l) → BH+ (aq) + OH- (aq)

Strong acid:

• Completely WHAT 

• Concentration are WHAT 

Strong acid:

• Completely DISSOCIATES 

• [HA]i = [A-] = [H3O+]

How do you find pH through an acid

pH = -log[H3O+] at 25 celcius

Weak acid:

• Concentrations are WHAT 

• [HA]i doesn’t = [A-]e = [H3O+]

Strong base:

• Completely WHAT 

• Concentration are WHAT 

Strong base:

• Completely DISSOCIATED 

• [B]i = [BH+] = [OH-]

How do you find pH of a base 

pOH = -log[OH-] 

pH = 14 - pOH at 25 celcius

Weak acid:

• Concentrations are WHAT 

Weak acid:

• [B]i doesn’t = [BH+]e = [OH-]

Equation for Ka (acids)

Ka = [A-][H3O+] / [HA]

Equation for Kb (bases)

Kb = [BH+][OH-] / [B]

OR

Kb =  [HA][OH-] / [A-]

What is Kw equal to 

Kw = [H3O+][OH-]

Kw = 1.0×10^-14 at 25 celcius 

pKa = WHAT 

Ka = WHAT 

pH = WHAT 

[H3O+] = WHAT 

pKa = -log(Ka) 

Ka = 10^-pKa

pH = -log(H+)  

[H3O+] = 10^-pH  

pKb = WHAT 

Kb = WHAT 

pOH = WHAT 

[OH-] = WHAT 

pKb = -log(Kb)  

Kb = 10^-pKb 

pOH = -log(OH-)   

[OH-] = 10^-pOH 

An acidic solution is WHAT

[H3O+] > [OH-] (not always less than 7)

An neutral solution is WHAT

[H3O+] = [OH-] (not always 7 )

An basic solution is WHAT

[H3O+] < [OH-] (not always more than 7) 

Strong acid

• Reacts completely with WATER, leaving the CONJUGATE BASE and H3O+ 

• HUGE Ka values 

• 7 strong acids (on data sheet)

Weak acids HA + H2O →← A- + H3O+

• Does not completely react with water. At equilibrium you have HA, A- and H3O+ present 

• Moderate Ka value 

In very weak acids

Do not react with water therefore do not produce H3O+ in water

An increase in Ka = a WHAT in kPa therefore the solution is a WHAT since it produces more products (WHAT)

An increase in Ka = a DECREASE in kPa therefore the solution is a STRONG ACID since it produces more products (H3O+)

An increase in Kb = a WHAT in kPb therefore the solution is a WHAT since it produces more products (WHAT)

An increase in Kb = a DECREASE in kPb therefore the solution is a STONG BASE since it produces more products (OH-)

The stronger the acid the WHAT the conjugate base

The stronger the acid the WEAKER the conjugate base

Conjugate bases of Strong acids and conjugate acids of strong bases do not HWAT

Are very weak acids or bases therefore do not react with water to produce H3O+ or OH-

%dissociation / %ionization

• Percentage of a WHAT that dissociates in solution 

• A good way to describe the WHAT of your acid 

• The STRONGER the acid, the WHAT the % dissociation 

%dissociation / %ionization

• Percentage of a ACID/BASE that dissociates in solution 

• A good way to describe the STRENGTH of your acid 

• The STRONGER the acid, the LARGER the % dissociation 

How to calculate %dissociation / ionization

1. Starting with a HA (weak acid) 

• % dissociation = [A-]equilibrium / [HA]initial x 100%

2. Starting with HA + A- (buffer) 

• % dissociation = [A-]equilibrium / [HA]equilibrium + [A-]equilibrium x 100%

Soluble salts are those that WHAT into WATER

Soluble salts are those that DISSOCIATE 100% into WATER

Many acids are delivered not as their fully protonated forms, but as salts of their WHAT or WHAT (eg, Ammonium chloride, Sodium acetate) 

Many acids are delivered not as their fully protonated forms, but as salts of their CONJUGATE ACID or BASE (eg, Ammonium chloride, Sodium acetate) 

Predicting if a salt solution will generally be acidic basic or neutral can help direct WHAT 

Equilibrium calculations 

Generally salts that cause a change in pH are called WHAT as they react with water in solution

Generally salts that cause a change in pH are called HYDROLYZING SALTS as they react with water in solution

Ions will only react if the “conjugate” makes a WHAT or WHAT

Ions will only react if the “conjugate” makes a WEAK ACID or WEAK BASE

Steps to determine pH of salt solutions

1. Determine ions in salt 

2. Determine if ions react with water 

3. Determine pH