Acids,bases + salts

Acid

A species that is a proton donor

PH less than

7

Strong acids

Acids that fully dissociate in water

Examples of strong acids

H2SO4, HCl, HNO3

H2SO4

Suluric acid

HNO3

Nitric acid

Weak acids

Acids that only partially dissociate in water

Examples of weak acids

C6H8O7, HCOOH + other carboxylic acids, CH3COOH

C6H8O7

Citric acid

HCOOH

Methanoic acids

CH3COOH

Ethanoic acid

Ion released when acids split up not component ions

H+

Examples f mono basic acid

HCl

Example of dibasic acid

H2SO4

Example of tribasic acid

H3PO4

When does dissociation not occur

When reactions are reversible

Bases

Species that are proton acceptors

What do bases tend to have

Species with lone pairs

Common bases

Metal oxides and hydroxides

Examples of metal oxides

MgO, CuO

Examples of metal hydroxides

NaOH, Mg(OH)2

What are all amines

Bases eg CH3NH2

What can b Sid about the relationship between alkalis and bases

Al alkalis are bases but not all bases are alkalis

Alkalis

A type of base that dissolve in water to form a hydroxide ion

Alkalis have a pH greater than

7

Alkalis have a pH greater than

7

Common alkalis

So idus hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH3)

Easy way to tell is acids or alkalis are strong or weak

Strong are irreversible reactions, weak have double headed arrow= reversible reaction

Is ammonia a strong or weak alkali

Weak

What can amino acids be described as being and why

A substance that can behave as both and acid and as a base

Show how amino acids are amphoteric

H-N-H is the amine group which is a base, OH-C—O is a carboxyl group which is acidic

Salts

An ionic compound formed from an acid when the H+ ion has been replaced by a metal ion or other positive ion eg NH4+

Features of salts

Positive cation in a salt is usually a metal ion or an ammonium ion, negative ion is derived from the acid

Sulfuric acid goes to what salt

Sulfate salts- NaOH + H2SO4→ Na2SO4

Hydrochloride acid goes to what salt

Chloride salts eg HCl→ NaCl

Nitric acid goes to what salt

Nitrate salts eg HNO3→ Ca(NO3)2

Acid + base/alkali=

Salt + water

Acid + metal carbonate→

Salt + carbon dioxide + water

Acid + metal→

Salt + hydrogen

Example of MASH

2Na + 2HCl → 2NaCl + H2

Example of acid + base

2HCl + MgO → MgCl2 + H2O

Example of metal carbonate + acid

2HCl + CaCO3 → CaCl2 + CO2 + H2O