2.4 Period 3 Flashcards
What are the types of each element in period 3?
Sodium, magnesium and aluminium = metallic
Silicon = metalloid
Phosphorus, sulfur and chlorine = non-metals
Argon = Nobel gas
Which elements do we need to know that react with water?
Sodium and magnesium
Information about reaction between sodium and water?
Sodium reacts ionically to form a 1+ positive ion
2Na + 2H2O -> 2NaOH + H2
This reaction is vigorous - fizzes rapidly
Less energy is required to ionise sodium (than Mg) therefore sodium is more reactive
Information about reaction between magnesium and water?
Magnesium reacts ionically to form a 2+ positive ion
Mg + 2H2O -> Mg(OH)2 + H2
This reaction is slow
How can we change the speed of the magnesium + water reaction?
By using steam instead of water provides greater energy resulting in a violent reaction
Mg + H2O(g) -> MgO(s) + H2
Magnesium burns with a bright white flame
How do we react period 3 elements with oxygen?
Using a gas jar containing oxygen
The combustion spoon (with the sample) is placed inside the jar after being heated
What are the products of period 3 elements and oxygen?
Na2O MgO Al2O3 SiO2 P4O10 SO2 SO3
Information about sodium and oxygen?
Sodium is stored under oil to stop it reacting with water vapour in the air = need to dab oil off
Burns with a yellow flame
Produces a white powder (shown as a white mist)
Universal indicator solution goes: Purple
pH: 14
Na2O(s) - ionic
Information about magnesium and oxygen?
Magnesium has a reactive oxide layer - scraped off with sandpaper
Burns with a white flame
Produces a white powder (shown as a white mist)
Universal indicator solution goes: Purple
pH: 10
MgO(s) - ionic
Information about aluminium and oxygen?
Aluminium is an explosive grey powder
Burns with a white flame and gives orange sparks
Produces a white powder (shown as a white mist)
Universal indicator solution goes: Green
pH: 7
Al2O3(s) - ionic (with a degree of covalency)
Information about silicon and oxygen?
You have to heat it very strongly for a reaction
pH: 7
SiO2 - macromolecular
Information about phosphorus and oxygen?
Red phosphorus is used (white phosphorus will react in air spontaneously) - allotropes
Burns with a orange flame
Produces a white powder (shown as a white mist)
Universal indicator solution goes: Red
pH: 1
P4O10(s) - covalent
P4O6 - can be formed with a lack of O2
Information about sulfur and oxygen?
Burns with a pale blue flame
Produces a colourless gas
Universal indicator solution goes: Red
SO2 - pH 3
SO3 can also form but requires high temperatures and a catalyst
pH 1
What are the natural formed of phosphorus and sulfur?
P4
S8
What is the bonding of period 3 oxides?
Na2O - ionic MgO - ionic Al2O3 - ionic (degree of covalency) SiO2 - macromolecular covalent P4O10 - covalent SO2 - covalent