sc8, acids and alkalis (paper 1)

Question 1

acids have a pH of

Answer 1

less than 7

Question 2

alkalis have a pH of

Answer 2

more than 7

Question 3

acids are a source of what ions

Answer 3

hydrogen, H+

Question 4

alkalis are a source of what ions

Answer 4

hydroxide, OH-

Question 5

true or false: strong acids dissociate completely in water producing higher concentrations of H+ ions, whereas weak acids have incomplete dissociation

Answer 5

true

Question 6

true or false: strong acids dissociate incompletely in water producing lower concentrations of H+ ions, whereas weak acids have complete dissociation

Answer 6

false

Question 7

why can a dilute solution of a strong acid have a similar pH and reactivity as a concentrated weak acid

Answer 7

because they have a similar concentration of hydrogen ions

Question 8

define neutralisation

Answer 8

an acid that reacts with a base to form a neutral substance

Question 9

define base

Answer 9

a substance that neutralises an acid

Question 10

true or false: all alkalis are bases, but not all bases are alkalis

Answer 10

true

Question 11

true or false: all bases are alkalis, but not all alkalis are bases

Answer 11

false

Question 12

what does a base + acid produce

Answer 12

salt + water

Question 13

what does a metal + acid produce

Answer 13

salt + hydrogen

Question 14

what does a metal carbonate + acid produce

Answer 14

salt + water + carbon dioxide

Question 15

how do you test for hydrogen

Answer 15

a lighted splinbt ignites hydrogen with a pop

Question 16

how do you test for carbon dioxide

Answer 16

turns limewater milky or cloudy white

Question 17

are nitrates soluble or insoluble

Answer 17

soluble

Question 18

are sodium, potassium and ammonium hydroxide soluble or insoluble

Answer 18

soluble

Question 19

are sodium, potassium and ammonium carbonate soluble or insoluble

Answer 19

soluble

Question 20

are common chlorides, sulfates soluble or insoluble

Answer 20

soluble

Question 21

are sodium, potassium and ammonium salts soluble or insoluble

Answer 21

soluble

Question 22

are silver and lead chloride soluble or insoluble

Answer 22

insoluble

Question 23

are lead, barium and calcium sulfate soluble or insoluble

Answer 23

insoluble

Question 24

are common hydroxides soluble or insoluble

Answer 24

insoluble

Question 25

are common carbonates soluble or insoluble

Answer 25

insoluble

Question 26

how is a precipitate formed

Answer 26

when you combine two aqueous solutions of soluble ionic compounds

Question 27

define precipitate

Answer 27

an insoluble product

Question 28

what colour is red litmus paper in acids

Answer 28

red

Question 29

what colour is blue litmus paper in acids

Answer 29

red

Question 30

what colour is methyl orange in acids

Answer 30

red

Question 31

what colour is phenophthalein in acids

Answer 31

colourless

Question 32

what colour is red litmus paper in alkalis

Answer 32

blue

Question 33

what colour is blue litmus paper in alkalis

Answer 33

blue

Question 34

what colour is methyl orange in alkalis

Answer 34

yellow

Question 35

what colour is phenophthalein in alkalis

Answer 35

pink