pH, acids and bases, and buffers

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, weak 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 is…

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

Reaction of acids with water forms…

H3O+

Reaction of Base with water forms…

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

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

Base + Acid

Salt + Water

Ammonia + Acid

Ammonium Salt

Ionic equations

separate into ions and cancel

strong acids/bases conductivity

high conductivity

weak acids/bases conductivity

conduct electricity to a slight extent

Conductivity experiments can be used to…

distinguish between strong and weak acids/bases of equal concentration

distinguishing between strong and weak acids/bases can be done through…

conductivity, pH, and Rate of reaction

Acid Rain pH

less than 5.6

acid rain

caused by increasing emissions of the nitrogen and sulphur oxides

Acid rain formula

CO2 (g) + H2O (l) = H2CO3 (aq) or SO2 (g) + H2O (l) = H2SO3 (aq)

Equivalence point

when you have equal amounts in mole of the strong acid/base and the weak base/acid

half equivalence point

[HA]=[A-] and pKa=pH, this is where you have the optimal buffer in a solution

To get a buffer you can…

1. add equal amounts (in mol) of salt of the weak acid/base and strong base/acid and the solution of weak acid/base (it will be at half equivalence point)

2. titrate the weak acid/base with the strong base/acid until the ideal pH, which will be when pH=pKa (of the weak acid/base)

Acid dissociation constant, K_a

The equilibrium constant for how much an acid dissociates in water, a high K_a value indicates a stronger acid

K_a= [H⁺] [A^-] / [HA]

Base dissociation constant, K_b

The equilibrium constant for how much a base dissociates in water, a higher K_b value indicates a stronger acid

K_b= [BH⁺] [BA^-] / [B]