Chapter 11: Acid, Bases and Salts

Question 1

acid

Answer 1

a substance that dissolves in water producing H+ (ap) ions and is a proton donor. It has a pH below 7.

Question 2

corrosive

Answer 2

a corrosive substance is one that can dissolve or eat away at other materials (wood, metals or human skin).

Question 3

nitric acid

Answer 3

HNO3

Question 4

sulphuric acid

Answer 4

H2SO4

Question 5

hydrochloric

Answer 5

HCl

Question 6

ethanoic acid

Answer 6

CH3COOH

Question 7

indicator

Answer 7

a substance that changes colour when added to acidic or alkaline solutions eg litmus, thymolphthalein.

Question 8

thymolphthaliem

Answer 8

an acid-base indicator that is colourless in acidic solutions and blue in alkaline solutions.

Question 9

methyl orange

Answer 9

an acid-base indicator that is red in acidic and yellow in alkaline solutions.

Question 10

base

Answer 10

substances that neutralizations an acid-producing salt and water as the only products, base act as proton accepters.

Question 11

alkalis

Answer 11

soluble bases that produce OH- (aq) ions in water have a pH above 7

Question 12

Universal indicator

Answer 12

a mixture of indicators that have different colours in solutions with different pH.

Question 13

conductivity f acids

Answer 13

conducts electricity better than distilled water due to ions being present in the acid.
water has equal numbers of H and OH ions while acids have excess in H and alkalis have excess in OH.

Question 14

neutralisation

Answer 14

a chemical reaction between an acid and a base to produce salt and water only; summarised by the ionic equation H+(aq) + OH-(aq) –> H2O(l)

Question 15

ammonium nitrate + sodium hydroxide —>

Answer 15

sodium nitrate + water + ammonia

Ammonia is more volatile than sodium, ammonia gas is detected by turning litmus paper blue.

Question 16

acidic oxides

Answer 16

oxides of non-metals that will react with bases and dissolve in water to produce acid solutions.

Question 17

basic oxides

Answer 17

oxide of a metal that will react with acids to neutralise the acid.

Question 18

how does sulfur react

Answer 18

burns with bright blue flames

Question 19

how does phosphorus react

Answer 19

burns with yellow flame

Question 20

how does carbon react

Answer 20

glows red

Question 21

how does sodium react

Answer 21

burns with yellow flame

Question 22

how does magnesium react

Answer 22

burns with bright white flame

Question 23

how does calcium react

Answer 23

burns with red flame

Question 24

how does iron react

Answer 24

burns with yellow sparks

Question 25

how does copper react

Answer 25

does not burn turns black

Question 26

amphoteric compound

Answer 26

a compound (hydroxide or metal oxide) that reacts with both an aid and alkali to give salt and water. Zinc and Aluminium (only metal oxides)

Question 27

metal + acid

Answer 27

salt + hydrogen

Question 28

acid + base

Answer 28

salt + water

Question 29

acid + metal carbonate

Answer 29

salt + water + carbon dioxide

Question 30

test for carbonate

Answer 30

dilute hydrochloric acid is added to the unknown salt and if carbon dioxide is given off then salt is a carbonate.

Question 31

strong acid

Answer 31

an acid that is completely ionised when dissolved in water- this produces the highest possible concentration of H+ (aq) ions in solution.

Question 32

weak acid

Answer 32

an acid that is only partially dissociated into ions in the water usually produces a low concentration of H+(aq) in the solution. eg ethanoic acid.

Question 33

dissociation

Answer 33

the separation of a covalent molecule into the ions when dissolved in water.

Question 34

equilibrium

Answer 34

the process of dissociation is reversible in weak acids and can go either direction. Once the weak acid or alkali has dissolved the solution reaches an equilibrium position. hence the use of reversible arrows in the equation.