chemical changes topic 3

Question 1

hoe can you measure a ph

Answer 1

using an indicator or a ph probe

e.g a universal indicator

Question 2

what is an acid

Answer 2

any substances that forms aqueous solutions with a ph less than 7 because they ionise to release hydrogen ions

Question 3

what is a bases

Answer 3

any substance with a ph greater than 7

Question 4

what is an alkali

Answer 4

a subgroup of a base that dissolves in water to form a solution greater than water

Question 5

what ions do alkalis form when dissolves in water

Answer 5

hydroxide ions

Question 6

what ions do acids form when when dissolved in water

Answer 6

hydrogen ion

Question 7

acid plus an bases

Answer 7

neutralization reaction making a salt and water

Question 8

bases end with a

Answer 8

hydroxide or carbonnate

Question 9

what are strong acids

Answer 9

all of the acid particles will disociate to release hydrogen ions or the reactants completely tunr into products

Question 10

what are weak acids

Answer 10

only a small portion of particles will disociate to release hydrogen ions

Question 11

why do weak acids only discoiate a small protion of partcles to relase hydrogen ions

Answer 11

this is because the ionsation of a weak acid is irreversable

Question 12

what is a ph scale

Answer 12

a measure on how acid or alkali a substance is

or a measure of the contrenation of hydrogen ions in a solution

Question 13

how is a ph probe more accurate than a universal incator

Answer 13

as it doesn’t need human judgement it just has a result written on it

Question 14

what happens in a reversable reaction of an acid

Answer 14

at the equilibrum lys to the left so we would have far more molecules of unidssiociated acid thand dissociated acid

Question 15

what is concentration

Answer 15

how much subtsnace there is with a certain volume

Question 16

what is the trend down the ph scale

Answer 16

as the contration of hydrogen ions gets higher the ph gets lower. each decrease of the number by one in theph scale shows the increase of hydrogen ions would be times 10

Question 17

what is the term for acid plus a metal oxide
acid plus a metal hudroxide
acid plus carbonate

Answer 17

reversable reactions

Question 18

acid plus a metal oxide

Answer 18

salt and water

Question 19

acid plus a metal hydroxide

Answer 19

salt plus water

Question 20

acid plus a metal carbonate

Answer 20

salt plus water plus carbon dioxide

Question 21

to make a soulable salt

Answer 21

acid plus an insoulable base(like a metal oxide , metal hydroxide or carbonate. you put a

Question 22

pratical to have a soulable salt

Answer 22

you have an acid on a busen burner and you add the insoulable base until there in an excees and the base is no longer disappearing . then you filtrer out the the excess. then you heat up the remaining solution and evaporate some of the waterusing a water bath . and then you leave it to crystalise them . then you filter out the crystals