IB Chemistry Acids and Bases

Hydrochloric Acid (formula, strength)

HCl, strong acid

Nitric Acid (formula, strength)

HNO3, Strong acid

Sulphuric Acid (formula, strength)

H2SO4, strong acid

phosphoric acid (formula, strength)

H3PO4, weaker acid

Ethanoic Acid (formula, strength)

CH3COOH, weak acid

Carbonic Acid (formula, strength)

H2CO3, weak acid

Sodium Hydroxide (formula, strength)

NaOH, strong base

Potassium Hydroxide (formula, strength)

KOH, strong base

Calcium Hydroxide (formula, strength)

Ca(OH)2, weaker base

Barium Hydroxide (formula, strength)

Ba(OH)2, weaker base

Ammonia (formula, strength)

NH3, weak base

Alkalies are...

bases that dissolve in water

An Acid is defined as

a proton donor (or a hydrogen ion donor as hydrogen ion consists of only one proton)

A base is defined as

a proton acceptor

A bronsted - lowry acid must have

an H in its formula

Ionization

when an acid is placed in water, the acid gives up its H+ ion forming hydronium ions (H3O+)

Reaction of acids with water

H3O+

Reaction of Base with water

OH-

Conjuctive acid-base pair

the acid and base that are related by the exchanging of a hydrogen ion

Conjugate base

when an acid loses a proton, the species produced is referred to as the conjunctive base

Polyprotic species

acids capable of donating more than 1 hydrogen ion

monoprotic acid

can donate only 1 hydrogen ion

diprotic acid

can donate 2 hydrogen ions thus 2 reactions will occur

triptoproic acid

can donate 3 hydrogen ions

Amphiprotic

can act as either a base or an acid. e.g. HSO4-, HCO3-, H2O

Properties of acids

Sour taste
blue litmus red
corrosive
molecular in structure
conduct electricity

Acid + Metal

Salt + Hydrogen Gas

Acid + Metal hydroxides

Salt + Water

Acid + Metal Oxides

Salt + Water

Acid + Metal Carbonates

Salt + Water + Carbon Dioxide

Acid + Metal Hydrogen Carbonates

Salt + Water + Carbon Dioxide

Acid pH

Less than 7

Base pH

Greater than 7

positive ion

goes first

Base properties (taste, litmus, Feel, Conductivity)

taste bitter
turn red litmus blue
feel slippery
conducts electricity

Base + Acid

Salt + Water

Ammonia + Acid

Ammonium Salt

Ionic equations

separate into ions and cancel

A good indicator

gives a distinct colour change

Neutral pH

=7

Calculating pH

-log10 (H+)

Calculating H+

10^-pH

if the pH changes by 1

then the concentration changes by a factor of 10

H3O+ x OH- =

10^-14

H+ x OH- =

10^-14

Concentration =

Number of mol divided by Volume

concentration units

mol dm^-3

A strong acid and arrow

ionises completely, single headed arrow

a weak acid and arrow

ionises partially, double headed arrow

strong acids - conjugate base

weak conjugate base

strong acids conductivity

high conductivity

weak acids conductivity

conduct electricity to a slight extent

Strong bases

ionise completely

weak bases

ionise only partially

Steong bases conductivity

good conductivity

weak bases conductivity

Poor conductivity

Conductivity experiments

can be used to distinguish between strong and weak acids of equal concentration same with bases

distinguishing between strong and weak acids

conductivity
pH
Rate of reaction (metal carbonate + Acid)

Acid Rain pH

less than 5.6

acid rain

increasing emmisions of the nitrogen and sulphur oxides

Acid rain formula

CO2 (g) + H2O (l) = H2CO3 (aq)

Sulphur dioxide and water

SO2 (g) + H2O (l) = H2SO3 (aq)
H2SO3 (g) + H2O (l) = H3O+ (aq) + HSO3- (aq)

coal combustion

S (s) + O2 (g) = SO2 (g)

sulphur dioxide with oxygen

2SO2 (g) + O2 (g) = 2SO3 (g)

Sulphuric trioxide with rain

SO3 (g) + H2O (l) = H2SO4 (aq)

Nitrogen with oxygen

N2 (g) + O2 (g) = 2NO (g)

Nitrogen (II) oxide with oxygen

2NO (g) + O2 (g) = 2NO2 (g)

Nitrogen dioxide with water

2NO2 (g) + H2O (l) = HNO3 (aq) + HNO2 (aq)

NO with oxygen

2NO (g) + O2 (g) = 2NO2
2HNO2 (aq) + O2 (g) = 2HNO3