salt

Question 1

all salts are ____ compounds

Answer 1

ionic

Question 2

salts can be made by reacting ____ with ___,____,____,___

Answer 2

acids; metals, carbonates, bases, or alkalis

Question 3

acid + metals->

Answer 3

salt + hydrogen gas

Question 4

acid + carbonate

Answer 4

salt + water + co2

Question 5

acid + base/alkali

Answer 5

salt + water

Question 6

what happens during the reaction to form salt

Answer 6

one or more h+ ions of an acid is replaced by a metallic ion or ammonium ion, forming a metallic salt or ammonium salt

Question 7

def salt

Answer 7

a compound formed when the hydrogen ion in an acid is replaced by a metallic ion or an ammonium ion

Question 8

anion ->

cation->

Answer 8

acid

metal, carbonate, bases/alkali

Question 9

how is an acid salt form

Answer 9

one or more replaceable hydrogen ion remains in the salt

Question 10

why is an acid salt called acid salt

Answer 10

acid→ dissolves in water to produce hydrogen ions

salt→ hydrogen ion(s) has been replaced by a metal/ammonium ion

Question 11

how do salts form crystals

Answer 11

many salts combine with water molecules to form crystals

these water molecules are known as water of crystallisaiton

Question 12

what are salts that do not contain water of crystallisation called, and what form are they usually in

Answer 12

anhydrous salts; powders

Question 13

formula with water of crystallisaiton:
copper (II) sulfate
magnesium sulphate
sodium carbonate
zinc sulphate
iron sulphate

Answer 13

CuSO4.5H2O
MgSO4.7H2O
Na2CO3.10H2O
ZnSO4.7H2O
FeSO4.7H2O

Question 14

are all nitrates soluble

Answer 14

yes

Question 15

are all A1 salts soluble (SPA salts)

Answer 15

yes

Question 16

are carbonates soluble

Answer 16

no, only A1 carbonate salts are soluble

Question 17

are chlorides soluble

Answer 17

yes except silver chloride; lead (II) chloride (souble in hot water)

Question 18

are sulfates soluble

Answer 18

yes except calcium sulfate; barium sulfate ; lead (II) sulfate

Question 19

qns ask to decide how to make salt

Answer 19

1) is the salt soluble?

no→ precipitation method

yes→2) is it A1 salt?

no→ acid +123

yes→ titration

Question 20

what is the 123 in acid + 123

Answer 20

excess metal/insoluble base/ insoluble carbonate

Question 21

why must 123 be added in excess

Answer 21

make sure all the acid is used up, otherwise, the salt produced will be contaminated by the acid

Question 22

why must the base and carbonate be insoluble in water

Answer 22

to allow the excess substance to be filtered from the salt solution produced

Question 23

how to know if reaction is completed in acid +123 and what are the steps after

Answer 23

the reaction is completed when there is unreacted 123 in the soln

the mixture is filtered to remove any excess metal/base/carbonate

filtrate which contains soluble salt is head until 1/3 and cooled. upon cooling, crystals will form.

FWD

Question 24

is effervescence observed in acid +metal

Answer 24

yes

Question 25

stirring

Answer 25

ensure even mixing of reactant

Question 26

(hot)dilute acid

Answer 26

to speed up the reaction as hot acid reacts faster than cold acid

Question 27

(excess) metal

Answer 27

to ensure that all the acid is used up

Question 28

filtered

Answer 28

to remove any unreacted metal

Question 29

heated to evaporate most of the water

Answer 29

produces a saturated solution

Question 30

do not evaporate to dryness

Answer 30

1) to ensure hydrated crystals will not lose their water of crystallisation 2) any impurities will be left in the remaining solution after cooling and not in the crystals

Question 31

upon cooling

Answer 31

to allow crystals to form as upon cooling, crystal's solubility is decreased, thus encouraging crystallisaiton

Question 32

what metals are not suitable for acid +123 and why

Answer 32

not suitable for very reactive metals→potassium, sodium, calcium unreactive metals→copper silver gold platinum

Question 33

true or false: acid + base has effervescence

Answer 33

false. acid + base no effervescence, acid + carbonate have

Question 34

titration method why cannot know when reaction complete

Answer 34

no residue can be seen

Question 35

steps for titration

Answer 35

1) known volume of alkali transferred by pipette to a conical flask 2) add an indicator 3) place acid in a burette. the alkali is then titrated against the acid until the indicator changes colour 4) note the volume of acid used from the burette 5) repeat procedure without adding indicator 6) heat solution until it is saturated and allow it to cool. crystals will form 7) FWD

Question 36

uses of silver salts

Answer 36

photography

Question 37

salts used in food preservatives

Answer 37

sodium nitrate, sodium sulfite, sodium citrate

Question 38

salts used in food flavoring

Answer 38

sodium chloride, monosodium glutamate

Question 39

salts used in fertilizers

Answer 39

ammonium sulfate, ammonium nitrate

Question 40

precipitation method forms an insoluble salt by

Answer 40

mixing the solns of two soluble salts

Question 41

insoluble salt will be formed as

Answer 41

precipitate

Question 42

steps to precipitation method

Answer 42

1) mix solutions of soluble salts 2) filter mixture and keep the residue 3) wash n dry