Chemical Properties of Period 3

what period 3 elements react with cold water

Na and Mg

equation and what is seen when Na reacts with cold water

2Na(s) + 2H₂O (l) → 2NaOH(aq) + H₂ (g)

_{Reacts vigoursly}

Acidiy of 2NaOH and how to measure acidity

to measure solution: add 1 mol Na₂o + 1dm³ H₂O

very alkeline , pH = 13-14

equation and what is seen when Mg reacts with cold water

Mg(s) + 2H₂O(l) → Mg(OH)₂ (aq) + H₂ (g)

very slow reaction

pH levels of Mg(OH)₂

pH 9-10 , because less solouble

equation and what is seen when Mg reacts with steam

Mg(s) + 2H₂O (l) → MgO (s) + H₂

faster reaction

birght white flame , white smoke

equation and what is seen when Na reacts with oxygen

4Na (s) + O₂ (g) → 2Na₂O

burn bright yellow flame

what does Na₂O

white powder

may be a yellow poweder if excess oxygen

Na(s) + O₂ (g) → Na₂O₂

equation and what is seen when Mg reacts with oxygen

2Mg(s) + O₂ → 2MgO

what can be seen when Mg reacts with Oxygen

Bright white flame

2MgO → white powder

equation and what is seen when Al reacts with oxygen

4Al (s) + 3O₂ → 2Al₂O₃

High temp needed

what can be seen when Al reacts with Oxygen

burns with white flame

at room temp , forms aluminium oxide layer → extremly unreactive

equation and what is seen when Si reacts with oxygen

Si (s) + O₂ → SiO₂ (s)

what can be seen when Si reacts with Oxygen

white flame

2 types of phosphorous

white and red

diffrence between white and red phosporus

white - spontenisly ignites at room temp , produces white solid and white smoke

red- high temp

produces white solid and white smoke

equation and what is seen when P reacts with oxygen

4P (s) + 5O₂ (g) → P₄O₁₀

if not eneough oxygen how does phosphorus react with oxygen

4P(s) + 3O₂ (g) → P₄O₆ (s)

equation and what is seen when S reacts with oxygen

2S (s) + 3O₂ (g) → 2SO₃

what can be seen when S reacts with Oxygen

colourless , eggy smell

burns with blue flame

what is the strucute of Na₂O , MgO , Al₂O₃ and its melting point

ionic lattice , strong electrostatic attraction , lots of energy needed to break , so high mp

what is the strucute of SiO₂ and its melting point

Giant covalent structure , high Mp

strucuter of P₄O₁₀ , SO₃ , SO₂

simple covalent

order of melting point for P₄O₁₀ , SO₃ , SO₂ and why

P₄O₁₀ , SO₃ , SO₂

SO₃ , non polar , 1 more electron , so stronger van der waals , so stronger Mp , liquid at room temp

SO_{2 , GAS}

why does Al₂O₃ have some covalent charachter

Al smaller than Mg , Al stronger charge

distors electric cloud

why is SiO₂ is insolouable

water can not break giant covalent structre

Why is Al₂O₃ insoloauble

so strong lattice due to covalent charachter , no dissoacation , insoloauble

equation for Na₂O react with water

Na₂O + H₂O → 2Na⁺ + 2OH^-

soloubility and pH of Na₂O with water

very soluable

pH 13-14

equation for MgO react with water

MgO + H₂O → Mg(OH)₂

soloubility and pH of MgO with water

soluable

ph 9-10

equation for P₄O₁₀ react with water

P₄O₁₀ (s) + 6H₂O → 4H₃PO

soloubility and pH of P₄O₁₀ with water

pH 1-2

react vigoursly

shape of H₃PO

Tetrahedral

109.5

equation of SO₃ with water

SO₃ + H₂O → H₂SO₄

how does SO₃ react with water and pH

react vigoursly

pH - 0-1

what does H₂SO₄ shape

tetrahedral

109.5

equation for SO₂ with water and ph

SO₂ + H₂O → H₂SO₃ , SULFURIOUS ACID

not vigorous ph- 2-3

shape of H₂so₃

Trigonal pyramdial

107

what does Na₂O react with

acids , produces salt and water

what does MgO react with

acids

What does Al₂O₃ react with

Amphoteric

reacts with both acids and bases

reaction of Al₂O₃ with acids

Al₂O₃ (s) + 6HCl (aq) → 2AlCl₃ (aq) + 3H₂O (l)

reaction of Al₂O₃ with alkeline

Al₂O₃ (s) + 2NaOH (aq) + 3H₂O(l)→ 2NaAl(OH)₄ (aq)

what oxides react with bases

SiO₂ , P₄O₁₀, SO₃ , SO₂

equation of SiO₂ with bases and what is needed and what is seen

only strong bases

SiO₂ (aq) +2NaOH (aq) →Na₂SiO_{3 (aq)} +H₂O (l)

Hot conc NaOH

colourless solution of Na₂SiO₃

reaction of P₄O₁₀ with base

P₄O₁₀ (aq) +12NaOH (aq) → 4Na₃PO₄ (aq) +6H₂O (l)

vigirous reaction

reaction SO₂ with base

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

reaction SO₃ with base

SO₃ (l) + 2NaOh (aq) → Na₂SO (aq) + H₂O

vigorous reaction