chem unit 7 - acids, bases, and salts

acids + metals →

salt + H₂

acids + bases →

salt + H₂O

acids + carbonates →

salt + H₂O + CO₂

acids effect on litmus

red

acids effect on methyl orange

red

acids effect on thymolphthalein

colourless

define the term ‘bases’

oxides or hydroxides of metals

define the term ‘alkali’

soluble bases that release hydroxide ions in solution

bases + ammonium salts →

salt + water + NH₃

ex: NH₄Cl + NaOH → NaCl + H₂O + NH₃

alkali effect on litmus

blue

alkali effect on thymolphthalein

blue

alkali effect on methyl orange

yellow

what ions do aqueous solutions of acids contain?

H+ ions

what ions do aqueous solutions of alkalis contain?

OH- ions

ph scale

acids: pH less than 7

alkalis: pH greater than 7

neutral: pH exactly 7

(check from book)

neutralization reaction (water)

H+ (aq.) + OH- (aq.) → H₂O (l)

acids are proton ____

donors

bases are proton ____

acceptors

strong acid

an acid that is completely dissociated in aqueous solution

weak acid

an acid that is partially dissociated in aqueous solution

strong acid and its symbol equation

hydrochloric acid

HCl (aq) → H+ (aq) Cl- (aq)

weak acid and its symbol equation

ethanoic acid

CH₃COOH (aq) ⇌ H+ (aq) + CH₃COO- (aq)

3 types of oxides

1. acidic (non-metal oxides)

2. basic (metal oxides)

3. amphoteric

acidic oxides

• non-metal oxides

• SO₂

• CO₂

basic oxides

• metal oxides

• CaO

• CuO

amphoteric oxides

• react with acids and with bases to produce a salt and water

• ZnO

• Al₂O₃

• ZaP