Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry AQA A level > Period 3 Oxides > Flashcards

Period 3 Oxides Flashcards

1
Q

Periodicity (define)

A

The regular repeating pattern of physical or chemical properties going across periods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What’s the trend in atomic radius across period 3?

A

Atomic radii decrease across a period, because the increased number of protons create more positive charge attraction for electrons which are in the same shell with similar shielding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What’s the trend in first ionisation energy across a period?

A

There is a general trend across to increase. This is due to increasing number of protons as the electrons are being added to the same shell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two elements that deviate from the first ionisation energy trend?

A

Al and S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain why Al deviates from the first ionisation energy trend

A

Al has the first electron in the 3p Subshell which is higher in energy and further away in space, so easier to remove

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain why S deviates from the first ionisation energy trend

A

S has the first example of spin pair repulsion in 3p so is easier to remove.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

State and explain the trend in melting point of period 3 elements for the metals

A

For Na, Mg, Al-Metallic bonding : strong bonding-gets stronger the more electrons there are in the outer shell that are released to the sea of electrons. A smaller sized ion with a greater positive charge also makes the bonding stronger. Higher energy is needed to break bonds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

State and explain the trend in melting point of period 3 elements (including graph) for the non-metals

A

Si is Macromolecular: many strong covalent bonds between atoms, high energy needed to break covalent bonds-very high mp+bp
Cl2 (g), S8 (s), P4 (S)-simple molecular: weak van der waals between molecules, so little energy is needed to break them low mp + bp
S8 has a higher mp than P4 because it has more electrons (S8=128)(P4=60) so has stronger van der waal’s forces between molecules. Ar is monoatomic has weak van der waal’s forces between atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What’s the graph to show the trend in melting point of period 3?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

First ionisation energy definition

A

The enthalpy change when 1 mole of gaseous atoms have 1 mole of electrons removed from them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Generic equation for first ionisation

A

X(g) –> X+(g) + e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give the equations for the reaction of Na with water

A

2 Na (s) + 2 H2O (l) –> 2 NaOH (aq) + H2(g)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give the equation for the reaction of Mg with steam

A

Mg (s) + H2O (g) –> MgO (s) + H2(g)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Colour of flame and product of combustion of Na and equation

A

Yellow flame with a white solid
4 Na (s) + O2(g) –> 2 Na2O (s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Colour of flame and product of combustion of Mg and equation

A

White flame, White solid.
2Mg (s) + O2(g)–> 2MgO (s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Colour of flame and product of combustion of Al and equation

A

White flame, White Solid,
4Al + 3O2(g) –> 2Al2O3(s)

17
Q

Colour of flame and product and equation for the reaction between oxygen and Si

A

White flame, White solid
Si + O2(g) –> SiO2(s)

18
Q

Colour of flame and product and equation for the reaction between oxygen and P

A

White flame, White solid
4P + 5O2(g) –> P4O10(s)

19
Q

Colour of flame and product and equation for the reaction between oxygen and S

A

Blue flame, forms a choking gas
S+ O2(g) –> SO2(g)
S+ 3/2 O2(g) –> SO3(g)

20
Q

Trend in Melting point of ionic period 3 oxides (metal oxides)

A

The metal oxides (Na2O, MgO, Al2O3) are ionic. They have high melting points. They have Ionic giant lattice structures: strong forces of attraction between ions so higher mp. The increased charge on the cation makes the ionic forces stronger (bigger lattice enthalpies of dissociation) going from Na to Al so leading to increasing melting points.

21
Q

Trend in period 3 Melting points - SiO2

A

SiO2is Macromolecular: It has many very strong covalent bonds between atoms. High energy needed to break the many strong covalent bonds-very high mp +bp

22
Q

Simple molecular oxides

A

P4O10 (s), SO2(g), SO3(g) are simple molecular with weak intermolecular forces between molecules (van der waals + permanent dipoles) so have lower mp’s.

23
Q

Sodium Oxide with water (pH and equation)

A

Na2O (s) + H2O (l) –> 2Na+(aq) + 2OH-(aq)
pH 13

24
Q

Magnesium Oxide with water (pH and equation)

A

MgO (s) + H2O (l)–> Mg(OH)2(s)
Product will form white precipitate as sparingly soluble
pH 9

25
Q

Al2O3 or SiO2 with water and pH

A

Al2O3 and SiO2 do not dissolve in water because of the high strength of the Al2O3 ionic lattice and the SiO2 macromolecular structure, so they give a neutral pH 7

26
Q

Acid base reactions - how does Al2O3 react? Equations?

A

Aluminium oxide can act as both an acid and an alkali and is therefore called amphoteric Aluminum oxide acting as a base:
Al2O3 (s)+ 3H2SO4 (aq)–> Al2(SO4)3 (aq) + 3H2O (l)
Al2O3 + 6HCl –> 2AlCl3 + 3H2O
Or ionic: Al2O3 + 6H+ –> 2Al3+ + 3H2O

Aluminum oxide acting as an acid

Al2O3 (s)+ 2NaOH (aq) + 3H2O (l) –> 2NaAl(OH)4(aq) (this equation needs learning carefully)
Al2O3 (s)+ 2OH- (aq) + 3H2O (l) –> 2Al(OH)4- (aq)

27
Q

What do the simple molecular period 3 oxides make when reacting with water?

A

Acids

28
Q

What’s the trend in the reactions of the period 3 oxides with water?

A

The trend is the ionic metal oxides show basic behaviour and the non-metal covalent oxides show acidic behaviour. The slightly intermediate nature of the bonding in aluminium oxide is reflected in its amphoteric behaviour: it can act as both a base and an acid

29
Q

Phosphorus oxide + water and pH

A

P4O10(s) + 6 H2O (l)–> 4 H3PO4(aq)
pH 0

30
Q

Sulfur dioxide with water and pH

A

SO2(g) + H2O (l)–>H2SO3(aq)
pH 3 (weak acid)

31
Q

Sulfur trioxide with water and pH

A

SO3(g) + H2O (l)–> H2SO4(aq)
pH 0

32
Q

Reactions of the basic oxides with acids

A

Na2O (s) + 2 HCl (aq)–>2NaCl (aq) + H2O (l)
Na2O (s) + H2SO4(aq)–>Na2SO4(aq) + H2O (l)
MgO (s) + 2 HCl (aq)–>MgCl2(aq) + H2O (l)

33
Q

Equations for the acidic oxides reacting with bases

A

P4O10(s) + 12 NaOH (aq)–>4Na3PO4(aq) + 6 H2O (l)
P4O10+ 6 Na2O–>4Na3PO4
SO2(g) + 2NaOH (aq)–>Na2SO3(aq) + H2O (l)
SO3(g) + 2NaOH(aq)–>Na2SO4(aq) + H2O (l)

34
Q

Macromolecular oxide reactions with base

A

2NaOH (l) + SiO2(s)–> Na2SiO3(aq) + H2O
It is still classed as an acidic oxide

35
Q

Define amphoteric

A

Chemical can react as an acid or a base

36
Q

Displayed formula for phosphoric acid, sulfuric (IV) acid and sulfuric (VI) acid

A

Chemistry AQA A level (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions