Chapter 5- Acids and Bases

Question 1

What are the properties of acids compared to bases?

Answer 1

Acids- sour, dissolve metals, neutralize bases

Bases- bitter, slippery, neutralize acids

Question 2

What are alkaloids?

Answer 2

Organic bases found in plants that are often poisonous

Question 3

What is the Arrhenius definition of acids and bases?

Answer 3

Acid: a substance that produces H+ ions in aqueous solution
Base: a substance that produces OH- ions in aqueous solution

Question 4

What is the brønsted-Lowry definition of acids and bases?

Answer 4

Acid: proton (H+ ion) donor
Base: proton (H+ ion) acceptor

Question 5

What does amphoteric mean?

Answer 5

Substances that can act as acids and bases

Brønsted-lowry definition is amphoteric

Question 6

What is a conjugate acid and a conjugate base?

Answer 6

Conjugate acid: the product that receives an H+ (ion) (it is the base with an extra H)
Conjugate base: the product that loses an H+ (ion) (it is the acid with a taken away H)

Question 7

What is a strong electrolyte compared to a weak electrolyte?
What about acids?
What about bases?

Answer 7

Strong electrolyte- completely dissociates into ions in solution
Weak electrolyte- only partially dissociates
Strong acid- completely ionizes in solution
Weak acid- only partially ionizes
Strong base- completely dissociates in solution
Weak base- only partially dissociates

Question 8

What are the 6 strong acids?

Answer 8

HCl- hydrochloric acid
HBr- hydrobromic acid
HI- hydroiodic acid
HNO3- Nitric Acid
HClO4- Perchloric acid
H2SO4- Sulfuric acid

Question 9

The stronger the acid, the _________ the conjugate base.

Answer 9

Weaker

Question 10

What do HA and A- symbolize?

Answer 10

HA- acid

A- - conjugate acid

Question 11

What is the acid ionization constant (Ka)?

Answer 11

Same formula as all K’s just doesn’t include H2O in reactants
FOR ACIDS
Kb is for bases

Question 12

What is autoionization?

What is it’s constant?

Answer 12

When water acts as a base and an acid and can react with itself

Has an ion product constant for water (Kw) instead of Ka
Which always equals 1.0x10^-14

Question 13

How do you know an acidic solution is acidic?

What about a basic solution?

Answer 13

Acidic- [H3O+] > [OH-]
pH < 7

Basic- [OH-] > [H3O+]
pH > 7

Question 14

If [H3O+] goes up, what does Ka, pH, pKa?

Answer 14

Ka goes up
pH goes down
pKa goes down

Question 15

What is the formula for finding pH?
pOH?
pKa?

Answer 15

pH= -log[H3O+]
pOH= -log[OH-]
pKa= -logKa

pH+pOH=14.00

Question 16

Is the concentration of H+ equal to the concentration of the strong acid in a strong acid solution?

Answer 16

Yes

Question 17

How do you solve a questions with weak acids concentrations given? (Since the weak acids concentration does not equal H3O’s concentration)

Answer 17

You create an ICE table and then solve for x by searching up the Ka and creating an equation
(Use small x approximation)

Question 18

How do you find the percent ionization of a weak acid?

NM

Answer 18

Percent ionization= concentration of ionized acid (usually x) / initial concentration of acid
All multiplied by 100

[H3O+] (equilibrium) / HA (x100)

Question 19

How is the percent ionization of a weak acid affected by the concentration of the acid?

Answer 19

The percent ionization of a weak acid decreases with increasing concentration of the acid

Question 20

What are the 6 strong bases?

Answer 20

LiOH- lithium hydroxide
NaOH- sodium hydroxide
KOH- potassium hydroxide
Sr(OH)2- strontium hydroxide
Ca(OH)2- calcium hydroxide
Ba(OH)2- barium hydroxide

Question 21

What is Cl- the conjugate base of?
What about F-?
What about NO3-?

Answer 21

Cl- HCl
F- HF
NO3- HNO3

Anion A- is the conjugate base of acid HA

Question 22

What is an anion what is the conjugate base of a weak acid?

Answer 22

A weak base

Question 25

What is the pH of the anions (conjugate base) of a strong acid?

Answer 25

They are pH neutral so neither acidic or basic

Question 26

What type of pH (acidic, basic neutral) can salts form?

Answer 26

They came form acidic, basic, or neutral solutions when dissolved in water since they contain a cation and an anion

Question 27

What are the four possibilities in salts pH of the solution? (Chart on page 285) (NM)

Answer 27

1. Salts where neither the cation or the anion act as an acid or base form pH neutral (cation is counterion of strong base, anion is conjugate base of strong acid) not equilibrium 2. Salts where cation does not act as an acid and the anion act as a base form basic solution (Cation is counterion of strong base, anion is conjugate base of weak acid) NaHCO3 3. Salts where the cation acts as an acid and the anion does not act as a base form acidic solution (cation is conjugate acid of weak base or metal ion, anion is conjugate base of strong acid) NH4Cl 4. Salts where cation acts as acid and anion acts as base form solutions in which the pH depends of strengths of acid and base (cation is conjugate acid of weak base or metal ion, anion is conjugate base of a weak acid)

Question 28

What is the Lewis model of acids and bases?

Answer 28

Lewis acid: electron pair acceptor (has empty orbital or rearranges to create empty orbital so it can accept electron pair) Lewis base: electron pair donor

Question 29

What is the equation connecting Ka, Kb, Kw?

Answer 29

Ka x Kb = Kw

Question 30

What are the three sections cations are divided into when considering them as weak acids? (NM)

Answer 30

Cations that are counterions of strong bases- (one of the 6 strong bases) pH neutral Cations that are the conjugate of weak bases- NH4+ to NH3, weak acid Cations that are small, highly charged metals- Al Fe, weakly acidic solutions

Question 31

What does pKa affect the strength of a base and an acid?

Answer 31

Base- stronger | Acid- weaker

Question 32

How do the equations differ for weak acids/bases and strong acids/bases?

Answer 32

Weak- add water to weak acid/base then add OH- or H3O+ as product Strong- it is just the strong base or acid dissociating or ionizing into the OH- or H3O+ and it’s by-product

Question 33

How do sig figs work with logs?

Answer 33

However many sig figs are in the log calculation are how many decimal places after the decimal in the answer

Question 34

When do you classify a salt as pH neutral?

Answer 34

If the anion and cation are both from strong acids and bases Ex: NaCl Ca(NO3)2

Question 35

When do you classify a salt as basic?

Answer 35

Where the cation is from a strong base but the anion is from a weak acid Ex: NaF KNO2

Question 36

When do you classify a salt as acidic?

Answer 36

Where the cations are from weak bases and is small highly charged metal atom (conjugate acids of weak bases) and the anions are from strong acids Ex: FeCl3 Al(NO3)3 NH4Br

Question 37

When do you classify a salt as a pH that is dependant on relative strengths?

Answer 37

When the cation is from a weak base or a highly charged metal ion and the anion is from a weak acid