acids, bases, and salts flashcards DOUBLE CONTENT ONLY

definition of ‘acid’

a proton (H+) donor

definition of ‘base’

proton (H+) acceptor

definition of ‘alkali’

a type of base that donates OH- ions in water

what is the word equation for neutralisation?

acid + alkali → salt + water

what is the ionic equation for neutralisation?

H+ + OH- → H2O

strongly acidic pH and colour

0-3, red

weakly acidic pH and colour

4-6, orange/yellow

neutral pH and colour

7, green

weakly alkaline pH and colour

8-10, blue-green/blue

strongly alkaline pH and colour

11-14, blue/purple

flaw of universal indicator

it is a range of colours and not a clear colour change, also subjective

colour of methyll orange in acid

red

colour of methyll orange in alkali

yellow

colour of phenolphthalein in acid and neutral

colourless

colour of phenolphthalein in alkali

pink

colour of litmus in acid

red

colour of litmus in neutral

purple

colour of litmus in alkali

blue

what is the role of water in acidity?

it is needed for an acid to become acidic as acids cannot donate H+ ions unless they are aqueous

colour of copper oxide

base

colour of copper sulphate solution/crystals

blue

describe the process of making a soluble salt from an acid and an insoluble base

• heat the acid using a bunsen burner to increase the rate of reaction

• add the other reactant, stirring until no more will dissolve (saturated solution)

• filter the solution to remove excess solid

• put the solution into an evaporation basin

• heat until crystals form when a glass rod is dipped in the solution

• put on a window sill and leave for a few days

• filter off the excess solution

• dry the crystals in a drying oven

definition of acid strength

how many of the acid’s H+ ions are donated when aqueous

what is a strong acid?

an acid where all the H+ ions are fully dissociated (separate from the other ion)

what is a weak acid?

an acid where there is only partial dissociation of H+ ions

definition of concentration

moles per volume

what is a concentrated acid?

an acid with lots of moles in a fixed volume

what is a dilute acid?

an acid with not a lot of moles in a fixed volume

are compounds of sodium, potassium and ammonium soluble?

yes, always, even in normally insoluble compounds

are nitrates soluble?

always

are chlorides soluble?

yes, except for silver and lead (ii)

are sulfates soluble?

yes except for barium, calcium, and lead (ii)

are carbonates soluble?

no except sodium, potassium and ammonium

are hydroxides soluble?

no, except sodium, potassium and calcium

word equation for the reaction between a metal and an acid

metal + acid → salt + hydrogen

word equation for the reaction between a metal oxide and an acid

metal oxide + acid → salt + water

word equation for the reaction between a metal hydroxide and an acid

metal hydroxide + acid → salt + water

word equation for the reaction between a metal carbonate and an acid

metal carbonate + acid → salt + water + carbon dioxide