Periodicity Flashcards
Formula,
Reaction conditions,
Appearance of reaction,
flame colour
Product
of Na(s) + O2(g)
4Na(s) + O2(g) –> 2Na2O(s)
Heat
Vigorous
Bright yellow flame
White solid formed
Formula,
Reaction conditions,
Appearance of reaction,
flame colour
Product
of Mg(s) + O2(g)
4Mg(s) + O2(g) –> 2MgO(s)
Heat
Vigorous
Bright White flame
White solid formed
Formula,
Reaction conditions,
Appearance of reaction,
flame colour
Product
of Al(s) + O2(g)
4Al (s) + 3O2 (g) → 2Al2O3 (s)
heat powered Al
Fast
Bright white flame
White powder formed
Formula,
Reaction conditions,
Appearance of reaction,
flame colour
Product
of Si (s) + O2 (g)
Si (s) + O2 (g) → SiO2 (s)
Powdered Si Heat strongly
Slow
Bright white sparkles
White powder
Formula,
Reaction conditions,
Appearance of reaction,
flame colour
Product
of P (s) + O2 (g)
4P (s) + 5O2 (g) → P4O10 (s)
Heat
Vigorous
White flame
White clouds
Formula,
Reaction conditions,
Appearance of reaction,
flame colour
Product
of S (s) + O2 (g)
S (s) + O2 (g) → SO2 (g)
Powdered S Heated
Gentle
Blue flame
Toxic fumes
Formula
Reaction conditions
rate of reaction
of P (s) + Cl2 (g) →
2P (s) + 5Cl2 (g) → 2PCl5 (l)
Heat in excess chlorine
Slow
Formula
Appearance of reaction
Product
pH
of sodium and cold water
- 2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)
- Vigorous
- Hydrogen gas given off
solution formed is strongly alkaline(pH14)
Formula
Appearance of reaction
Product
pH
of Magnesium and cold water
- Mg (s) + 2H2O (l) → Mg(OH)2 (aq) + H2 (g)
- Extremely slowly
- Hydrogen gas produced,
weakly alkaline(pH 11)
Formula
Appearance of reaction
Product
of Magnesium and steam
- Mg (s) + H2O (g) → MgO (s) + H2 (g)
- Vigorous reaction
- hydrogen gas produced
Reaction of Al2O3 and Water
No Reaction as Al2O3 is soluble in water
Reaction of SiO2 and Water
No Reaction as SiO2 is soluble in water
Formula
pH
Appearance of reaction of P4O10(s) and water
Formula: H3PO4
pH: 3-4 (weakly acidic)
Vigorous reaction
Formula
pH of
SO2 and water
SO2 (s) + H2O (l) ⇌ H2SO3 (aq)
pH: 1-2 (Strongly acidic)
Formula
pH of
SO3 and water
SO3 (s) + H2O (l) → H2SO4 (aq)
pH: 1-2 (strongly acidic)
Is Al2O3 acidic/ amphoteric/ Basic
Amphoteric
Product of alkali + Acid (neutralization reaction)
Salt + Water
What is MgOH / MgO used for
Indigestion remedy（消化不良药） by neutralizing excess acid in the stomach
Observations of reactions of Al2O3 with acid and hot conc alkali
Reacts with acid to form salt and water
Reacts with hot, concentrated alkali to form salt
Equation of SiO2 (s) + 2NaOH (aq) →
SiO2 (s) + 2NaOH (aq) → Na2SiO3 (aq) + H2O (l)
Equation of P4O10 (s) + 12NaOH (aq) →
P4O10 (s) + 12NaOH (aq) → 4Na3PO4 (aq) + 6H2O (l)
NaCl in water
pH:
MgCl2 in water
pH:
NaCl (s) → Na⁺ (aq) + Cl⁻ (aq)
pH: 7
MgCl₂ (s) → Mg²⁺ (aq) + 2Cl⁻ (aq)
pH: 6
AlCl3 in water
pH:
Observation:
AlCl₃ (s) → Al³⁺ (aq) + 3Cl⁻ (aq)
pH: 4
Observation: White fumes of HCl
SiCl4 + Water
pH:
Observation:
SiCl₄ + 4H₂O → SiO2 + 4HCl
pH: 1
Observation: SiO2 as white ppt
white fumes of hydrogen chloride gas in rapid reaction, but dissolves in water to form acidic solution
