period 3. Flashcards
steadWhy is sodium more reacting than magnesium?
= lower ionisation energy
= energy required to remove an electron from sodium is lower than magnesium, more energy needed for mg to react
What happens when sodium reacts with cold water?
= vigourously
= ball + fizzing
= gas produced is h2
= NaOh
what happens when mag nesiym reacts with cold water?
= slowly
= weak alkaline solution of mg(Oh)2, sparingly soluable, little oh- ions
reacts faster with steam, forming magnesium oxide, MgO
What happens when period 3 elements react with oxygen?
= oxides
What is formula for sodium oxide?
= Na2O
= na +1
= O 2-
= reacts fast with air
What is formula for magnesium oxide?
= MgO
mg2+
O2-
= very fast
What is the formula for alluminium oixde?
Al2O3
Al 3+
O-2
= slow (fast if powdered)
What is the formula of silicon dioixde?
SiO2
= slow
What is the reaction for phosphorous and oxygen?
= p4 + 5o2 => p4O10
= spontaneously combusts
What happens when sulfur reacts with oxygen?
S + O2 => So2
= oxidation number of +4
= with higher teperayire and ctaalyst So3 can be made, +6
= steadily burns
Why does Na2O MgO and Al2O3 have high melting points?
= forms solid ionic lattices, there are strong electrostatic forces of attraction between oppositley charged ions
= mgO has a higher boiling and melting point, as it forms a 2+ ions, therefore, attracted more strongly to oxygen
Why does Al2o3 have a lower melting point?
= Al3+ ion distorts electron cloud of oxygen, this means there is some polarisation, there is some covalent character, pulls the electrons from the oxygen to itself, less energy is required to break the bonds
Why does sio2 have a large melting and boiling point?
= sio2 is a large macromilecular structyre, htere are many covalent bonds, these are strong andrequire a great deal of energy to break,
Why is p4o2 and so2 have low melting anf boiling points?
= form simple molecular structures, weaker intermolecular forces (vanderwall forces) between the molecules, therefore requires little energy to break
What happens when ionic oxides are added to water?
= forms alkaline solutions
= contain o2- ions, this is a proton acceptor from water molecules when dissolved,
= oxide + water forms a hydroxide
=
What happens with sodium hydroxide dissolves in water?
= dissolves in water
= has a high Ph
How does magnesium oxide dissolves ?
= sparingly in water
= alkaline solution is not strong
= lower ph
What happens when simple covalent oxides are added to water?
= forms acidic solution when added to water
= forms acid with a low Ph
What happens when p4o10 reacts with water?
p4O10 + 6H2o => 4H3Po4
H3Po4 => 3h+ + Po4 2-
What happens when so2 reacts wth water?
So2 + h2O => h2So3
H2So3 => 2H+ + So32-
What happens when so3 reacts with water?
= So3 + h2o => H2So4
= H2So4 => 2H+ + So42-
What happens when silicon dioxide reacts with water?
= giant covalent sturctures, which have may strong covalent bonds, large amounrs of energy to break, so is insoluble,
= it will reacy with a base to form a salr, so it is an acid
What happebs when allimnium oxide reacts with watr?
= amphoteric
= has covalent and ionic characterm insoluable in water, however will react with acid and bases
What happens when SiO2 reacts with NaOH?
2NaOH with SiO2
forms Na2SiO3 and water
What happens if P4O10 reacts with NaoH?
= 12NaOH reacts with p4O10
= produces 4 Na3PO4 and 6 water
What happens if So2 reacts with NaOH?
2NaOH racts with So2 forms Na2So3 and water
What happens when you react NaOH and so3?
2NaOh + So3 forms Na2So4 and water
What happens when NaOh reacts with Al2O3
= 2NaOH reacts with Al2O3 and water to form 2NaAl(OH)4
What happens when Al2O3 reacts with sulfuroc acid?
= 3 sulfuroc acid molecules, and allumnoum oixde
= Al2(So4)3 and 3 water molecules.
