period 3 Flashcards
1
Q
type of structure Na Mg Al
A
giant lattice
2
Q
type of structure Si
A
macromolecular
3
Q
type of structure P4 S8 Cl2
A
simple covalent molecules
4
Q
type of structure Ar
A
mono atomic
5
Q
type of bonding Na Mg Al
A
metallic
6
Q
type of bonding Si P4 S8 Cl2
A
covalent
7
Q
type of forces Na Mg Al
A
metallic bonds- attraction between positively charged metal ions and delocalised electrons in a lattice
8
Q
type of forces Si
A
covalent- shared pair of electrons
9
Q
type of forces P4 S8 Cl2
A
VDWs- temporary induced intermolecular forces
10
Q
type of forces Ar
A
VDWs
11
Q
bp and mp Na Mg Al Si
A
increasingly high
12
Q
bp and mp P4 S8 Cl2 Ar
A
low- weak forces
13
Q
trend across period in atomic radius
A
decreases
14
Q
why does atomic radius decrease across period
A
- more protons
- electrons added to same shell so shielding is same
- attraction between nucleus and outer electrons increases
15
Q
trend cross period first IE
A
increases
16
Q
why does first IE increase across period
A
- -more protons
- electrons added to same shell so shielding is same
- attraction between nucleus and outer electrons increases
17
Q
trend in electronegativity across period
A
increases
18
Q
observations of sodium with water
A
fizzes and floats on surface
Na dissolves
19
Q
sodium and water equation
A
Na+H2O > NaOH + 1/2H2
20
Q
observations of magnesium with cold water
A
- v slow reaction
- occasional bubble
21
Q
equation magnesium and cold water
A
Mg + H2O> Mg(OH)2 + H2
22
Q
observation magnesium with steam
A
- white flame
- white solid
23
Q
equation magnesium with steam
A
Mg + H2O > MgO + H2
24
Q
why is aluminium unreactive with water
A
-resistant to further oxidation because of Al2O3 coating
25
do silicon, phosphorus and sulphur react with water
no
26
observations chlorine and water
(with universal indicator paper)
| red then bleaches white
27
equation chlorine and water
Cl2 + H2O >< HClO + HCl
28
what is the reaction of water and chlorine an example of
disproportionation- chlorine simultaneously oxidised and reduced
29
does argon react with water
no
30
what do the period 3 elements react with oxygen to form
they react exothermically to form oxides, with the exception of chlorine and argon
31
observation sodium and oxygen
- orange/yellow flame
| - white solid
32
equation sodium and oxygen
4Na + O2 > 2Na2O
33
observation magnesium and oxygen
- white flame
| - white solid
34
equation magnesium and oxygen
Mg + 1/2O2 > MgO
35
observation aluminium and oxygen
- unreactive due to Al2O3 coating
| - fine powder- white sparkles/white solid
36
equation aluminium and oxygen
4Al + 3O2 > 2Al2O3
37
what kind of compounds are the metal oxides
basic
38
observations silicon with oxygen
v slow
39
equation silicon with oxygen
Si+ O2 > SiO2
40
observations phosphorus and oxygen
white flames and fumes
41
equation phosphorus and oxygen
4P + 5O2 > P4O10
42
observations sulphur and oxygen
blue flame
| choking gas
43
equation sulphur and oxygen
S + O2 > SO2
44
what kind of compounds are non metal oxides
acidic compounds
45
what can sulphur (IV) oxide (SO2) react with oxygen to form
sulphur (VI) oxide (SO3)
46
sulphur 4 oxide and oxygen
SO2 + 1/2O2> SO3
47
contact process
SO3 + H2O > H2SO4
48
why do NA20, MGO AND AL203 have high melting points
ionic- strong electrostatic attractions between oppositely charged ions require a lot of energy to break
49
why does SiO2 have a higher melting point than P4O10
SiO2 macromolecular and P4O10 is simple molecular
| strong covalent bonds in SiO2 require more energy to break than weak VDW forces between P4O10 molecules
50
why does P4O10 have a higher melting point that SO3
- P4O10 larger molecules-more electrons than SO3
| - p4o10 stronger VDW forces between molecules- more energy to break
51
in general, what do metal oxides from period 3 elements react with water to form
solutions containing hydroxide ions
52
sodium oxide and water equation
Na2O + H2O > 2NaOH
53
pH of resulting solution Na2O and H2O
Na2O is soluble and resulting solution has pH 11-14
54
magnesium oxide and water equation
MgO + H2O > Mg(OH)2
55
pH of resulting solution MgO and H2O
sparingly soluble- pH 8-10
56
is Al2O3 soluble in water
no- pH remains 7
57
what do non metal oxides of period 3 elements react with water to form
solutions containing H+ ions
58
SiO2 and water solubility?
insoluble- sand
59
P4O10 and water equation
P4O10 + 6H2O > 4H3PO4
60
pH of resulting solution P4O10 and WATER
1-2- STRONG ACID
61
SO2 and water equation
SO2 + H2O > H2SO3
62
pH of resulting solution SO2 and water
2-4- weak acid
63
equation SO3 and water
SO3 + H2O > H2SO4
64
pH of resulting solution SO3
0-2
65
examples of ionic oxides
Na2O and MgO
66
what do ionic oxides react with acids to form and why
salt and water
they are basic
67
equation sodium oxide and sulphuric acid
Na2O + H2SO4 > Na2SO4 + H2O
68
equation magnesium oxide and hydrochloric acid
MgO + 2HCl > MgCl2 + H2O
69
examples of covalent oxides
SiO2, P4O10, SO2, SO3
70
what do covalent oxides react with aqueous alkali to form and why
salt and water- theyre acidic
71
equation silicon oxide and sodium hydroxide
SiO2 + NaOH > Na2SiO3 + H2O
72
equation phosphorus (v) oxide and sodium hydroxide
P2O5 + 6NaOH > 2Na3PO4 + 3H2O
73
equation sulphur (IV) oxide and sodium hydroxide
SO2 + NaOH > Na2SO3 + H2O
74
equation sulphur (VI) oxide and sodium hydroxide
SO3 + NaOH > Na2SO4 + H2O
75
why does aluminium react with both acids and bases
its amphoteric
76
equation aluminium oxide and hydrochloric acid
Al2O3 + 6HCl > 2AlCl3 + 3H2O
77
equation aluminium oxide and nitric acid
Al2O3 + 6HNO3 > 2Al(NO3)3 + 3H2O
78
equation aluminium oxide and sodium hydroxide
Al2O3 + 2NaOH + 3H2O > 2NaAl(OH)4
79
what do aluminium salts form when dissolved in water
acidic solutions
80
why do aluminium salts form acidic solutions when dissolved in water
the ionic lattice breaks down and the Al3+ ions become surrounded by water forming a hexaaqua ion
81
hexaagua ion
[Al(H2O)6]3+
82
how many water molecules is the Al3+ ion surrounded by
6
83
how is each water molecule bonded to the aluminium ion
coordinate bond
84
what does the charge on the Al3+ ion cause the electron density in the water molecule to do
move closer to the metal ion- water molecule polarised
85
what does the Al3+ ion have enough polarising power to do
weaken the OH bonds in water- one of bonds breaks and a proton donated
86
equation for hexaagua ion losing proton
[Al(H2O)6]3+ > [Al(H2O)5(OH)]2+ + H+
87
what does adding a base to an aqueous solution of the hexaaqua aluminium ion produce
an insoluble precipitate of aluminium hydroxide
88
equation for hexaaqua ion and hydroxide ion
[Al(H2O6)]3+ + OH- > [Al(H2O)5(OH)]2+ + H2O
89
what happens to the equilibrium if you add more OH- ions to the hexaaqua aluminium ion
shifts to RHS to oppose change and reduce OH concentration and a new equilibrium is set up
90
what new equilibrium is set up when more OH- ions are added to alumium hexaaqua ions
[Al(H2O)5(OH)]2+ + OH- <> [Al(H2O4)(OH2)]+ + H2O
91
what final equilibrium is set up when even more OH- ions are added to aluminium hexaaqua ion
[Al(H2O)4(OH2)]+ + OH- <> [Al(H2O)3(OH)3] + H2O
92
why is the white precipitate formed from the final equilibrium of aluminium hexaaqua ion insoluble and why does it precipitate out
its neutral
93
overall equation for equilibrium of hexaagua ion
[Al(H2O)6]3+ +3OH- > [Al(H2O)3(OH3)] + 3H2O
94
amphoteric
species that can act as an acid or base
95
equation aluminium hydroxide reacting with acid
[Al(H2O)3(OH)3] + H+ > [Al(H2O)6]3+
| simplified: Al(OH3) + H+ > Al3+ + 3H2O
96
what does the white precipitate of aluminium hydroxide dissolve to form
colourless solution
97
equation aluminium hydroxide reacting with base
[Al(H2O)3(OH)3] + OH- > [Al(H2O)2(OH)4]- + H2O
| simplified: Al(OH)3 + OH- > Al(OH)4-
