Period 3

Reaction of Na with O₂

Reaction of Na with O₂

4Na(s) + O₂ (g) —> 2Na₂O(s)

yellow flame

white solid formed

Reaction of Mg with O₂

2Mg(s) + O₂ (g) —> 2MgO(s)

bright white flame

white solid

Reaction of Al with O₂

4Al(s) + 3O₂ (g) —> 2Al₂O₃(s)

bright white flame

white solid

Reaction of P with O₂

4P (s) + 5O₂ (g) —> P₄O₁₀ (s)

white flame

yellow/white solid formed

Reaction of S with O₂

S (s) + O₂ (g) —> SO₂ (g)

blue flame

toxic fumes

Reaction of Na with Cl₂

2Na (s) + Cl₂ (g) —> 2NaCl (s)

yellow flame

white solid formed

Reaction of Mg with Cl₂

Mg (s) + Cl₂ (g) —> MgCl₂ (s)

bright white flame

white solid

Reaction of Al with Cl₂

2Al (s) + 3Cl₂ (g) —> 2AlCl₃ (s)

bright white flame

white solid

Reaction of Si with Cl₂

Si (s) + 2Cl₂ (g) —> SiCl₄ (l)

forms toxic colourless liquid

Reaction of P with Cl₂

2P (s) + 5Cl₂ (g) —> 2PCl₅ (s)

yellow/white solid formed

Reaction of Na with H₂O

2Na (s) + 2H₂O (l) —> 2NaOH (aq) + H_{2 (g)}

reacts vigorously with cold water

Reaction of Mg with H₂O

in cold water: Mg (s) + 2H₂O (l) —> Mg(OH)₂ (aq) + H₂ (g) slow reaction

in hot water: Mg (s) + H₂O (g) —> MgO (s) + H₂ (g) reacts vigorously with steam

Reaction of Na₂O with H₂O

Na₂O (s) + H₂O (l) —> 2NaOH (aq)

pH of 12-14 (strongly alkaline)

Reaction of MgO with H₂O

MgO (s) + H₂O (l) —> Mg(OH)₂ (aq)

pH of 8-10 (weakly alkaline)

Reaction of Al₂O₃ with H₂O

no reaction

Al₂O₃ is insoluble in water

Reaction of SiO₂ with H₂O

no reaction

SiO₂ is insoluble in water

Reaction of P₄O₁₀ with H₂O

P₄O₁₀ (s) + 6H₂O (l) —> 4H₃PO₄ (aq)

pH of 3-4 (weakly acidic)

Reaction of SO₂ and with SO₃ with H₂O

SO₂ (g) + H₂O (l) —> H₂SO₃ (aq)

SO₃ (g) + H₂O (l) —> H₂SO₄ (aq)

pH of 1-2 (strongly acidic)

Reaction of Na₂O with HCl

Na₂O (s) + 2HCl (aq) —> 2NaCl (aq) + H₂O (l)

Reaction of MgO with HCl

MgO (s) + 2HCl (aq) —> MgCl₂ (aq) + H₂O (l)

Reaction of Al₂O₃ with H₂SO₄ and NaOH

Al₂O₃ (s) + 3H₂SO₄ (aq) —> Al₂(SO₄)₃ (aq) + 3H₂O (l)

reacts with acid to form salt and water

Al₂O₃ (s) + 3NaOH (aq) + 3H₂O (l) —> NaAl(OH)₄ (aq)

reacts with hot, concentrated alkali to form a salt

Reaction of SiO₂ with NaOH

SiO₂ (s) + 2NaOH (aq) —> Na₂SiO₃ (aq) + H₂O (l)

reacts with hot, concentrated alkali to form a salt and water

Reaction of P₄O₁₀ with NaOH

P₄O₁₀ (s) + 12NaOH (aq) —> 4Na₃PO₄ (aq) + 6H₂O (l)

Reaction of SO₂ and SO₃ with NaOH

SO₂ (g) + 2NaOH (aq) —> Na₂SO₃ (aq) + H₂O (l)

SO₃ (g) + 2NaOH (aq) —> Na₂SO₄ (aq) + H₂O (l)