5. Acids, Bases and Salts

Question 1

pH of acids

Answer 1

Below 7

Question 2

pH of neutral

Answer 2

7.0

Question 3

pH of alkalis

Answer 3

Above 7

Question 4

Difference between alkalis and bases

Answer 4

Alkalis are soluble bases

Question 5

Colour chart for UI

Answer 5

pH 1-2 = red
pH 3-4 = orange
pH 5-6 = yellow
pH 7 = green
pH 8-9 = blue-green
pH 10 = blue
pH 11-14 = purple

Question 6

Other indicators

Answer 6

Methyl orange, phenolphthalein

Question 7

Colour change in phenolphthalein

Answer 7

Acid = colourless
Alkali = pink

Question 8

Colour change in methyl orange

Answer 8

Acid = red
Alkali = orange

Question 9

Formula of hydrochloric acid

Answer 9

HCl

Question 10

Formula of nitric acid

Answer 10

HNO3

Question 11

Formula of sulfuric acid

Answer 11

H2SO4

Question 12

Difference between hydrogen chloride and hydrochloric acid

Answer 12

Hydrogen chloride is a gas - HCl(g). It has covalent bonding. When dissolved in water HCl(aq) it becomes an acid and releases H+ ions

Question 13

Arrhenius definition of an acid

Answer 13

Substance that releases H+ ions in water

Question 14

Bronsted Lowry definition of an acid

Answer 14

proton (H+ ion) donor

Question 15

Arrhenius definition of an alkali

Answer 15

Substance that releases OH- ions in water

Question 16

Bronsted Lowry definition of an alkali

Answer 16

proton (H+ ion) acceptor

Question 17

Definition of a strong acid

Answer 17

Fully dissociates in water e.g. HCl –> H+ + Cl-

Question 18

Definition of a weak acid

Answer 18

Only partially dissociates in water e.g HF <=> H+ + F-

Question 19

Which metals react with acids?

Answer 19

Those above hydrogen in the reactivity series. (not Cu, Ag, Au)

Question 20

Products of acid and metal

Answer 20

salt and hydogen

Question 21

acid and metal carbonate produces

Answer 21

salt + water + carbon dioxide

Question 22

acid + alkali

Answer 22

salt + water

Question 23

acid + ammonia

Answer 23

salt

Question 24

ionic equation for neutralisation

Answer 24

H+ + OH- –> H2O

Question 25

ionic equation for acid and metal carbonate

Answer 25

H+ + CO3 2- --> H2O + CO2