chap1, form 5 Flashcards
1
Q
oxidation: oxygen
A
gain
2
Q
oxidation: hydrogen
A
lose
3
Q
oxidation: oxidation number
A
increase
4
Q
oxidation: electron
A
lose
5
Q
U-TUBE: how many substances are at +ve terminal
A
6
6
Q
U-TUBE: what are the substances at +ve terminal
A
KMnO4 K2Cr2O7 Cl2 Br2 FeCl3 H2O2 KKCaukeBangladeshForHenry
7
Q
U-TUBE: how many substances are at -ve terminal
A
6
8
Q
U-TUBE: what are the substances at -ve terminal
A
KI KBr reactive metals FeSO4 SO2 KKRempitForSofia
9
Q
what are reactive metals not used in u-tube
A
Cu and Ag
10
Q
colour change of Fe2+
A
green to yellow
11
Q
colour change of Fe3+
A
orange to brown
12
Q
colour of Cu2+
A
blue
13
Q
colour change of KMNO4
A
purple to colourless
14
Q
colour change of K2Cr2O7
A
orange to green
15
Q
colour change of Cl2
A
greenish yellow to colourless
16
Q
colour change of Br2
A
orange to colourless
17
Q
colour change of FeCl3
A
yellow to green
18
Q
colour change of KI
A
colourless to yellow
19
Q
colour change of KBr
A
colourless to orange
20
Q
colour change of FeSO4
A
green to yellow
21
Q
function of salt bridge
A
allow movement of ions between electrolytes
22
Q
function of galvanometer
A
shows transfer of electrons
23
Q
function of arrow
A
shows movement of electrons
24
Q
U-TUBE: what happens at positive terminal
A
reduction
25
U-TUBE: what happens at negative terminal
oxidation
26
what are the 2 displacement reactions?
halogen displacement
| metal displacement
27
in halogen displacement, it involves which group?
group 17
28
how is the reactivity in G17?
going down group, reactivity decreases
29
how do you know its a halide?
it has -ides at the back
30
what is the strongest oxidising agent in G17?
flouride
31
what is the strongest reducing agent in G17?
astatide
32
why does the blue colour of copper nitrate become paler?
the concentration of Cu2+ ion decreases
33
colour of copper metal
brown
34
ECS gimme the order
kalau kahwin nak, mesti ada zakat fitrah supaya perkahwinan helok kekal abadi
35
what is the EO value of H2
0 V
36
all metal ions are __ agent
oxidising
37
all metals are ___agent
reducing
38
what is the strongest oxidising agent in ECS?
silver ion
39
what is the strongest reducing agent in ECS?
potassium, K
40
what happens at cathode?
reduction
41
what happens at anode?
oxidation
42
arrangement of cell notation for voltaic cell
anode: cathode
| metal/metal ion/metal
43
how to find E0 of cell
| if given +ve and -ve terminal
E0(+ve terminal) - E0(-ve terminal)
44
how to find E0 of cell
| if given cathode and anode
E0 cathode - E0 anode
45
what is the energy change that happens in voltaic cells?
chemical energy to electrical energy
46
function of voltaic cell
to supply electrical energy
47
ionic equation of anode depends on?
type of metal
48
how to determine which metal at anode? what are the requirements?
more reactive metal
49
how to determine which metal at cathode? what are the requirements?
less reactive metal
50
ionic equation of cathode depends on?
electrolyte
51
in electrolytic cell, the anode is connected to the ___terminal of battery
positive
52
in electrolytic cell, the cathode is connected to the ___terminal of battery
negative
53
in electroplating, at cathode what is put there?
the object plated
54
in electroplating, at anode what is put there?
metal for electroplating
55
in purification of metals, at cathode what is put there?
pure metal OR pure copper
56
in purification of metals, at anode what is put there?
impure metal OR impure copper
57
cathode attracts
cation
58
anode attracts
anion
59
for inert electrodes, what metals are used?
carbon, platinum
60
definition of electrolysis
a process where compounds in molten state or aqueous decompose into their constituent elements by passing electricity through them
61
what is energy change at electrolytic cell
electrical energy to chemical energy
62
for cathode, take cation with ___ E0 value
more positive
63
for anode, take anion with ____E0 value
less positive
64
if there is presence of hydrogen, oxygen gas what is the observation?
bubbles/effervescence
65
if there is presence of copper what is the observation?
brown deposition
66
if there is presence of silver, iron what is the observation?
shiny metal deposition
67
if there is presence of bromine gas what is the observation?
brown gas
68
if there is presence of lead what is the observation?
grey solid formed
69
electrolyte of electroplating contains what?
cations similar to anode
70
what is observation at cathode for electroplating?
shiny metal on surface of object
71
what is observation at anode for electroplating?
size of metal electrode has decreased
72
why is there shiny metal on surface of object?
there is metal coating on the object
73
why has the metal electrode decreased?
the electrode has deionised to release its ions in the electrolyte
74
for smooth coating of object, use ___electrical energy
low voltage
75
for smooth coating of object, _____slowly for ___
rotate object
| even distribution of metal on object
76
for smooth coating of object,
| ____of object with ___
clean surface
| sand paper to remove oxide layers before electroplating
77
what are the 2 insoluble carbonate salts?
silver carbonate
| copper(II) carbonate
78
what is the 1 insoluble chloride salt?
silver chloride
79
electrolyte of purification of metal has to be ____ with metal being purified
same
80
if copper was being purified, what electrolytes can be used? give 3
aqueous
CuSO4
CuCl2
Cu(NO3)2
81
carbon lining in extraction of aluminium act
| as
cathode
82
carbon/graphite electrodes in extraction of aluminium as
anodes
83
what is solution used in extraction of aluminium
molten aluminium oxide in molten cryolite
84
aluminium is extracted from
aluminium oxide or alumina
85
aluminium oxide is the purified version of?
bauxite or aluminium ore
86
what gas is released during extraction?
CO2
87
purification of bauxite creates
toxic red sludge
88
why does molten aluminium sink to the bottom?
high density
89
extraction of aluminium: what is the observation at cathode?
shiny deposition
90
extraction of aluminium: what is the observation at anode?
bubbles
91
why are there bubbles at anode?
there is presence of oxygen gas
92
why is there shiny deposition at cathode?
aluminium
93
3 function of cryolite
to lower melting point of bauxite from 2000 to 700
speed up production
reduce electrical cost
94
extraction of iron from hematite: what is added at the top? name 3
iron ore, coke, CaCO3
95
hematite chemical formula
Fe2O3
96
blast furnace used in
extraction of iron from hematite
97
extraction of iron from hematite: why hot air is supplied in? give 2 reasons.
increase rate of reaction
| less dense, so it move upwards to react with materials up there
98
slag aka
CaSiO3
99
density of slag
less dense than molten iron
100
what is reduced in carbon reduction process?
iron(III) oxide reduced
101
what happens in zone 1?
oxygen reacts with coke to form CO2
102
what happens in zone 2?
CO2 reacts with coke to form CO
103
what reduces iron(III) oxide to iron?
coke or CO
104
function of calcium carbonate/limestone?
decompose to form CaO/quicklime
105
function of CaO
neutralise and react with SiO2 to form CaSiO3
106
2 factors need for rusting
water, oxygen
107
rate of rusting is high in 2 situations. give them
high temperature
| salt/acid solution
108
why is the rate of rusting high in salt/acid solution?
there are free moving ions
109
explain how rusting of metal is a redox reaction
metal is oxidised spontaneously when metal atoms release electrons to form metal ions
110
the ___electropositive metal the easier to ____
more
| corrode
111
where is anode in rusting?
the very bottom yalls
112
what happens at anode in rusting?
iron ionises to become Fe2+
113
where is cathode in rusting?
at the very edge of droplet
114
what happens in cathode in rusting?
oxygen and water gain 4 electrons to form OH ion
115
how to indicate hydroxide ion in phenolphtalein?
pink
116
what happens after OH ion is formed?
the OH ion combine with Fe2+ to form iron(II) hydroxide
117
then what happens after iron(II) hydroxide is formed?
the iron(II) hydroxide will continue to react with oxygen to form rust
118
chemical name for rust?
hydrated iron (III) oxide
119
chemical formula for hydrated iron (III) oxide?
Fe2O3 x H2O
120
definition of galvanisation
a layer of zinc galvanises steel or iron
121
definition of tin plating/stanum
a layer of tin electroplates steel
122
characteristic of oxide layer
hard, non porous
123
another method to prevent rust starts with C
chrome plating
124
definition of sacrificial protection
iron is attached to a more electropositive metal
125
what happens to the more electropositive metal in ?sacrificial protection
it eventually corrodes, sacrificed
