acids and bases Flashcards by Misha Gandhi

State the arrhenius definition

Acids produce hydrogen ions in aq solutions and bases produce hydroxide ions in aq solutions

How well did you know this?

Not at all

Perfectly

State the bronsted-lowry definition

An acid is a proton donor and a base is a proton acceptor

How well did you know this?

Not at all

Perfectly

According to the bronsted-lowry definition what are acidic protons often attached to

Oxygen
Halogens
Nitrogen atoms

How well did you know this?

Not at all

Perfectly

According to the bronsted-lowry definition what do bases need

Lone pair electrons to act as a proton acceptor

How well did you know this?

Not at all

Perfectly

Acids and bases occur as what

Acid-base pairs
Base –> conjugate acid
Acid –> conjugate base

How well did you know this?

Not at all

Perfectly

What is ka

Acidity constant

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

How well did you know this?

Not at all

Perfectly

Describe strong acids

Most of acid is dissociated (ionized, strong electrolyte) 
Ka = large 
Equilibrium lies far right 
[H+]=[HA]initial 
A- much weaker base than H20

How well did you know this?

Not at all

Perfectly

State strong acids

HCl 
HI
HBR 
HNO3 
H2SO4 
HClO4

How well did you know this?

Not at all

Perfectly

Describe weak acids

Ka = small
Equilibrium lies far left
[H+] < [HA]initial
A- much stronger base than a H2O

How well did you know this?

Not at all

Perfectly

State weak acids

HF
CH3COOH (acetic acid)
HCOOH (formic acid)
HOOCCH2CCH2COOHCOOHOH (citric acid)

How well did you know this?

Not at all

Perfectly

Describe relationship between acid and base conjugate pairs

Inverse relationship
Strong acid –> doesn’t react as base (spectator)
Weak acid –> weak base
Doesn’t react as acid –> strong base

How well did you know this?

Not at all

Perfectly

What is water

Amphoteric

Acts as an acid or base

How well did you know this?

Not at all

Perfectly

What is Kw

Ion product constant of water

Kw=[H3O+][HO-] = 1.0x10^-14 @ 25degrees c

How well did you know this?

Not at all

Perfectly

What is Kw in neutral

[H30+]=[HO-] = x

Kw=x^2 –> x=1.0x10^-7

How well did you know this?

Not at all

Perfectly

What is Kw in acidic

[H30+]>[OH-]

How well did you know this?

Not at all

Perfectly

What is Kw in basic

[H30+] IS LESS THAN [OH-]

How well did you know this?

Not at all

Perfectly

State relationship between H+ and pH

As [H+] increases pH decreases

As [H+] decreases or [HO-] increases pH increases

How well did you know this?

Not at all

Perfectly

State formulas for the pH scale

Kw=[H3O+][HO-] = 1.0x10^-14 
pH = -log [H+]
pOH = -log [HO-]
-logKw = -log [H+]-log[HO-] = 1.0x10^-14 
Pkw = pH + pOH / pH+pOH = 14.00
[H+]= 10^-pH
[pOH] = 10^-pOH
*2 decimal places, 2 sig figs*

How well did you know this?

Not at all

Perfectly

State what percent dissociation is and the formula

Extent of ionization for a weak acid

%diss= (molarity of H+ at equil / initial concentration) x 100

How is percent dissociation affected as weak acid becomes more dilute

Increases

Formulas for pka, ka, kb and pkb

logpka=pka pka goes down ka goes up

- logpkb=pkb pkb goes down kb goes up

State formula for Kb

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

State strong bases

LiOH 
KOH 
NaOH 
RbOH 
CsOH 
Mg(OH)2
Ca(OH)2
Ba(OH)2
Sr(OH)2

State weak bases

Amines = ammonia, methylamine, ethylamine, aniline and pyridine
Hydroxylamines

What are polyprotic acids

Molecules that have more than one acidic proton

What is special about polyprotic acids

Product of 1st reaction = reactant of 2nd reaction | Each dissociation step has a Ka associated with it

How to solve weak polyprotic acids

Must do 2 ice tables and carry down [H+] from first table

How do we deal with something - x in acid base chemistry

Use 5% rule, approximation | If doesn't work then use quadratic formula

State the generalizations about WEAK polyprotic acids

All of [H+] comes from first dissociation step Very little of HA- dissociates, assume [H+]=[HA-] Concentration of [A2-]=ka2

How to solve strong polyprotic acids

Don't need ka1 --> first dissociation (first ice table) goes to completion Concentration of H+ carries down to the second ice table

What are salts

Ionic compounds that are products of acid-base neutralizations

Which salts do not affect pH

Salts of the cations of strong bases | Salts of the anions of strong acids

Which salt produces basic solutions

Salts containing cation (with neutral properties) and an anion that is the conjugate base of a weak acid

Which salt produces acidic solutions

Salts containing anion (with neutral properties) and a cation that is the conjugate acid of a weak base

State the relationship for any conjugate acid base pair

Inverse relationship between ka of acid and kb of base Ka x Kb = Kw PKa + PKb = 14.00

What do highly charged metal ions form

Complex ions and produce acidic solutions

What happens when both ions in a salt have acid-base properties

Competition between K's Ka>Kb pH < 7 acidic Ka=Kb pH = 7 neutral Ka is less than Kb ph is less than 7 = basic

What are covalent oxides

They produce acidic solutions | SO3, SO2, CO2, NO2, etc

What are ionic oxides

They produce basic solutions | CaO, K2O, etc

What is the relationship between acidity and increasing electronegativity

Proportional | Acidity increases when going down a column in periodic table

Describe hydrogen halides

Weak acid = strong bond | Strong acid = weak bond

Describe oxyacids

Electron withdrawing effect (inductive) of electronegative atoms makes the O-H bond more acidic

State lewis model definition

Lewis acid is an electron pair acceptor and a lewis base is an electron pair donor (Includes bronsted lowry acids and bases) Lewis base = e- pair donor Lewis acid = e- pair acceptor

Acid-base properties of salts: neutral salts

Cation is neutral (alkali metal or alkaline earth metal) Anion is conjugate base of a strong acid Ex = NaCl, KNO3

Acid-base properties of salts: basic salts

Cation is neutral (alkali metal or alkaline earth metal) Anion is conjugate base of a weak acid Ex = CH3COOHNa, NaCN

Acid-base properties of salts: acidic salts

Cation is conjugate acid of a weak base (or highly charges metal cation) Anion is the conjugate base of a strong acid Ex = NH4Cl, AlCl3