3.2.4 Properties of period 3 elements and their oxides Flashcards
Is sodium or magnesium more reactive?
Sodium (G1) is more reactive than magnesium (G2).
When they react they lose electrons to form Na+ and Mg2+.
Why is sodium more reactive than magnesium?
The amount of energy required to remove an outer electron from sodium is lower than it is to remove 2 electrons from magnesium. More energy is required for magnesium to react.
Explain the reaction between Sodium + water
reacts vigorously with cold water.
Forms a ball and fizzing
Gas produced is hydrogen (H2) and alkaline solution (NaOH).
Write out an equation to show the reaction of sodium with water.
2Na(s) + 2H2O(l) -> 2NaOH(aq) + H2(g)
Explain the reaction between magnesium and water.
reacts slowly with cold water, weak alkaline solution of Mg(OH)2 is formed = due to Mg(OH)2 being sparingly soluble = little OH- ions in solution.
Write an eqaution to show the reaction between magnesium and water.
Mg(s) + 2H2O(l) -> Mg(OH)2(aq) + H2(g)
Explain the reaction between magnesium and steam.
reacts more faster forming MgO
Write an equation to show the reaction between magnesium and steam.
Mg(s) + H2O(g) -> MgO(s) + H2(g)
When period 3 elements react with oxygen what do they form?
Oxides.
What element in period 3 is excepted with their reaction with oxygen and why?
Sulfur forms SO2 (oxidation state = +4).
With higher temperature and catalyst = oxidation state = +6
Sodium + oxygen
2Na(s) + 1/2O2(g) -> 2Na2O(s)
sodium oxide
Reaction with air: very fast
Magnesium and oxygen
Mg(s) + 1/2O2(g) -> MgO(s)
magenisum oxide
Reaction with air: Very fast
Aluminium and oxygen
2Al(s) + 1/2O2(g) -> Al2O3(s)
Aluminium oxide
Reaction with air: Slow (fast if powered as larger SA)
Silicon and oxygen
Si(s) + O2(g) -> SiO2(s)
Silicon dioxide
Reaction with air: slow
Phosphate and oxygen
P4(s) + 5O2(g) -> P4O10(s)
Phosphorous (v) oxide.
Reaction with air: Spontaneously combusts.
Sulfur and oxygen
S(s) + O2(g) -> SO2(g)
sulfur dioxide
Reaction with air: Steadily burns.
What affects the melting point of period 3 oxides?
Their structure and bonding.