inorganic Flashcards
melting point from Na to Al
-melting points increase from Na to Al
-because all three are only metallic bonding
-which increases across the period due to higher charge density
melting point at Si
-melting point increases significantly at Si
-because it is a macromolecular structure
-which has very strong pure covalent bonds
-that require a lot of energy to break
melting point at p
-melting point decreases significantly at p
-because it is only a simple covalent structure
-with only weak Van der Waals
melting point from S to Ar
-S has the highest melting point of the non-metal elements
-Cl is next
-Ar has the lowest melting point because it is the smallest (monatomic)
-Van der Waals forces are determined by size
;why does sulfur have slightly higher melting point than phosphorous
-Because S is larger than P
-S has 8 atoms whilst P has 4
-thus VDW forces are stronger
Trend in first ionisation energy across period 3
-increase across the period
-increased nuclear charge so stronger attraction between the nucleus and electrons
-radius decreased as a result
-no shielding across the period thus does not affect
trend in atomic radius across period 3
-decreases across period 3
-because proton is added each time
-so stronger attraction between positive nucleus and negative electrons
Reaction of Al with oxygen
burns vigorously with bright white flame
forms 2Al2O3
Reaction of Si with oxygen
burns with a bright white flame and white smoke
forms SiO2
Reaction of Na with oxygen
burns vigorously with yellow flame
forms 2Na2O
Reaction of Mg with oxygen
burns vigorously with a bright white flame
forms 2MgO
Reaction of P with oxygen
burns spontaneously with a bright white flame and smoke
forms P4O10
Reaction of S with oxygen
burns with a blue flame
forms SO2
Reaction of Na with water
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
Reaction of Mg with water
Slow in cold water:
Mg(s) + 2H20(l) → Mg(OH)2(aq) + H2(g)
Vigorous with steam:
Mg(s) + H20(l) → MgO(s) + H2(g)
Reaction of Cl with water
dissolves to form chlorine water:
Cl2(aq) + H2O(l) ⇌ HClO(aq) + HCl(aq)
Properties of Na20
bonding: ionic
structure: giant ionic lattice
melting point: high
Properties of MgO
bonding: ionic/covalent
structure: giant ionic lattice
melting point: high
Why is the melting point higher for Mg than for Na?
- Mg is smaller than Na
- Mg has a plus 2 charge whilst Na has a plus 1 charge
- so… stronger attraction between ions in MgO = higher melting point
Properties of Al2O3
bonding; ionic/covalent
structure: giant ionic lattice
melting point: high
Properties of SiO2
bonding: covalent
structure: giant covalent/ macromolecular
melting point: high
Properties of P4O10
bonding: covalent
structure: molecular
melting point: relatively low
properties of SO2 and SO3 and the difference between them
bonding: covalent
structure: molecular
melting point: relatively low
difference: SO2 is a gas at room temperature whilst SO3 is a liquid at room temperature
Reaction of NA2O with water
-ions present after reaction
-type of solution
-pH
Na+ (aq)
OH− (aq)
strongly alkaline
pH 13-14