2.4 Period 3 Flashcards
Appearance and physical properties of sodium
Metallic, shiny, conducts electricity (worst conductor out of the metals)
Reaction of sodium with acid
Na + acid –> H2 + Salt
Reaction of sodium with cold water and observations
2Na + 2H2O –> 2NaOH + H2
Vigorous reaction
Floats on water
Fizzes
pH = 13/14
Reaction of sodium with oxygen and observations
2Na+1/2O2 –> Na2O
Bright yellow flame, forms white powder
Appearance and physical properties of magnesium
Metallic, shiny, conducts electricity
Reaction of Mg with cold water
Mg + 2H2O –> H2 + Mg(OH)2
Very slow reaction
pH=10
Reaction of Mg with steam
Mg + H2O –> MgO + H2
Much faster
Reaction of mg with oxygen
2Mg + O2 –> 2MgO
Bright white flame
White powder
Appearance and physical properties of aluminium
Metallic, shiny, best conductor of electricity in period 3
Reaction of Al with cold water
No reaction
Reaction of Al with oxygen
4Al + 3O2 —> 2Al2O3
Bright flame
White powder
Appearance and physical properties of silicon
Semimetal, semi conductor
Reaction of silicon with oxygen
Si + O2 –> SiO2
White powder
Heat needed
Appearance and physical properties of phosphorus
Non-metal
Low mp and bp
Doesnt conduct electricity
Reaction of phosphorus in excess oxygen
4P + 5O2 —> P4O10
White solid
Reaction of phosphorus in limited oxygen
4P + 3O2 –> P4O6
Incomplete combustion
Colourless liquid phosphorus trioxide is formed
Appearance and physical properties of sulfur
Non metal
Low mp and bp
Doesnt conduct electricity
Reaction of sulfur with oxygen
S + O2 –> SO2
Heat needed
Colourless gas sulfur dioxide formed
What bonding does each period 3 oxide have
Na - ionic lattice
Mg - ionic lattice
Al - ionic lattice with covalent character
Si - giant covalent
P - simple molecular covalent
S - simple molecular covalent
What is the trend in mpt for period 3 oxides
Highest is MgO
Lowest is SO2
Increases along group for metals for Na2O and MgO due to stronger ionic bonding, Al2O3 is lower due to covalent character
Decreases with size for simple molecular molecules
Most basic period 3 oxides
Na2O and MgO
Reaction of Na oxide with water and its pH
Na2O + H2O –> 2Na+ + 2OH-
pH=14
Reaction of Mg oxide with water and its pH
MgO + H2O –> Mg2+ + 2OH- <—>Mg(OH)2
pH= 9-10
What are the products if Na2O and MgO are reacted with acid
Salt and water only