R3.1: Proton transfer reactions

Acids are good

conductors of electricity

Strong acids

disassociate completely into ions in water

Boron is stable with just 6 electrons but can

accept 2 more although it’s an exception to the octet rule

Bases are proton

acceptors

Acids are proton

donors

Older (Arrhenius’ definition) concluded that all acids have

[H+] and all bases have [OH-]

More relevant Brønsted & Lowry theory proposes that

Brønsted & Lowry acids are proton donors and Brønsted & Lowry bases are proton acceptors. Lewis acids are electron pair acceptors and Lewis base are electron pair donors

Acid disassociation is as follows

HA + H2O → A- + H3O+

Hydronium (H3O+) is the

main ion in acidic solution and follow iconic acid base behavior theory. It can also be expressed as [H+]

Binary acids are made of a halide and hydrogen and increase in strength

across a period and down a group. They include HF, HCl, HBr, and HI

Oxyacids acids are polyatomic ions including

HNO3, H2SO4, H2CO3, and H3PO4

Weak acids have strong

conjugate base pairs and vise versa

Strong acids have weak

conjugate base pairs and vise versa

A conjugate pair is made up of a substance and its form after

protonation or deprotonation

Conjugate pairs should only differ by

1 proton

Organic acids are almost exclusively

weak acids

Acids chip away

bases by donating protons

Mineral testing for calcite (CaCO3) includes a drop of

acid that causes the solution to bubble in calcite presence due to the reaction forming gas (CO2)

Monoprotic acids can only donate

1 H+

Diprotic acids can donate only

2 H+

Triprotic acids can donate only

3 H+

Alkali or alkali earth metals and oxygen or hydroxides make

common bases

Some weak bases are

NaHCO3 (sodium hydrogen carbonate),Na2CO3 (sodium carbonate), NH3 (ammonia), and CH3CH2NH2 (ethanamine)

Amphiprotic substances include

HCO3- (hydrogen carbonate ion), HSO4- (hydrogen sulfate ion), H2PO4- (dihydrogen phosphate), HPO4(2-) (hydrogen phosphate), and H2O (water)

Amphiprotic means to be able to either

donate or accept protons

Amphoteric means to be able to either

display acid or base behavior

All amphiprotic substances are amphoteric but not

all amphoteric substances are amphiprotic

The disassociation of a strong acid is

exothermic the acid is happy and stable as an ion

NH4+ is a coordinate bond where H is

not very happy because its electron are lost to the more electronegative oxygen

the pH scale is between 0 to 14 but can extend to

infinity and negative infinity

Lithmus indicator turns blue in the presence of

base

Lithmus indicator turns red in the presence of

acid

pH is calculated with [H+] with the formula

pH=-log[H+] where base = 10

pOH is calculated with [OH-] with the formula

pOH=-log[OH-] where base = 10

[OH-] is calculated with pOH with the formula

[OH-]=10^(-pOH)

[H+] is calculated with pH with the formula

[H+]=10^(-pH)

To convert from pOH to pH, you

subtract it from 14 [14-pOH=pH] and vise versa

For strong acids and bases, the initial concentration of

[H+] or [OH-] is the same as the substance due to complete disassociation.

Methyl orange turns red in the presence of

base

Methyl orange turns yellow in the presence of

acid

Phenolphthalein turns colorless in the presence of

acid

Phenolphthalein turns purple/pink in the presence of

base

The iconic product of water is the value of equilibrium (K) of [H+] and [OH-] ions at 298K

Kw=1×10^(-14)

Since pH of water = 7

[OH-] = [H+] for ionic product of water @298K

H2SO4 is diprotic but

only its first disassociation is strong

The strength of an acid or base depends on its

degree of dissociation

Organic often see as little as

1% being dissociated into H3O+

Increased [H3O+] or [OH-] mean

stronger rather than weaker acids

Strong acids/bases have

good conductivity, more extreme pH values, and fast reactions with CaCO3 and Mg

The side of the reaction expression with the stronger acids/bases will

be the position to which equilibrium is leaning to

Log scales are used to

linearize data

Antacids neutralize

stomach acids

Metal oxides and acids create water and salt

M-O + H-A → MA + H2O

Metal hydroxides will react with water to create water and salt

M-OH + H-A → M-A + H2O

Hydrocarbons might react with water to create water, salt, and carbon dioxide

M-H-CO3 + H-A → MA + H2O+ CO2

Carbonates might react with water to create water, salt, and carbon dioxide

M-CO3 + H-A → MA + H2O + CO2

Amines might react with water to create water, salt, and carbon dioxide

RNH2 + H-A → NH4+ + A-

Ammonia might react with water to create water, salt, and carbon dioxide

NH3 + H-A → NH4 + A-

with a pH increase or decrease of 1, [H+] =

100 times stronger or weaker

Titration allows us to find

the concentration of an unknown acid or base and titrate it with a standard solution of which you know the concentration and understand its significance

The titrant is put into a small burette and added to a measured volume of acid w/ clear concentration

At half of its reaction, when the indicator is colored, and equivalence point is reached, acid and base are of equal concentrations and neutralization of reaction is reached.

The indicator often used for titration is

phenolphthalein

The sharp change in pH on a pH curve for the progression of a titration is called the

point of inflection (POI)

Base added to acid shows a

pH increasing curve

Acid added to a base shows a

pH decreasing curve

Complete disassociation is usually an

irreversible process

Organic acids can only donate hydrogens in their

carboxylic function groups because C-H is not polar so would not dissolve in polar substance

Bonds are better shorter as they are less

“diluted”

Water doesn’t break as much as acids break into

ions rather than form new molecules by breaking water

More concentrated acids are more

corrosive

More concentrated acids are not more

strong

Stronger acids mean they are

better proton donors

Oxyacids increase in strength with increased

oxidation of the central atom

Binary acids increase in strength

across the group and down a period

HCl is

hydrochloric acid

HNO3 is

nitric acid

H2SO4 is

sulfuric acid

HBrO is

hydrobromic acid

HI is

hydroiodic acid

HClO4 is

Perchloric acid

HClO3 is

chloric acid

CH3COOH is

ethanoic acid

HCO3 is

carbonic acid

H3PO4 is

phosphoric acid

HF is

hydrogen fluoride

H2SO3 is

sulfurous acid

HNO2- is

nitrous acid

LiOH is

lithium hydroxide

NaOH is

sodium hydroxide

KOH is

potassium hydroxide

BaOH2 is

barium hydroxide

NaO is

sodium monoxide

Ca(OH)2 is

calcium hydroxide

NH3 is

ammonia

C2H5NH3 is

Ethylamine

strong acid + strong base =

neutral salt

strong acid + weak base =

acidic salt

weak acid + strong base =

basic salt

Transition metals do not form very

strong bases

Effervescence is

the fizzing or pop that comes from gas being produced in liquid and coming out as bubbles (observable)