SPM-Chemistry-Formula-List-Form5

# SPM-Chemistry-Formula-List-Form5 - ONE-SCHOOL.NET Short...

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ONE-SCHOOL.NET http://www.one-school.net/notes.html 1 Short Notes: Form 5 Chemistry Rate or Reaction Calculation Rate of Reaction (Average Rate) Quantity change of reactants/products Rates of reaction = Total time for the reaction If the quantity change is immeasurable 1 Rates of reaction = Total time for the reaction Find the Rate From a Graph Average Rate Rates At an Instant The rate of reaction is equal to the slope of the graph of quantity against time. Δ (Product) Rate of Reaction = Δ (Time) The rate of reaction at an instant, t, is equal to the slope of tangent at that instant. Δ (Product) Rate of Reaction = Δ (Time)

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ONE-SCHOOL.NET http://www.one-school.net/notes.html 2 Chemical Reaction Precipitation of Sulphur 2HCl (aq) + Na 2 S 2 O 3(aq) ⎯→ 2NaCl (aq) + S (s) + SO 2(g) + H 2 O (l) Notes: 1. Yellow precipitate (sulphur) is formed. 2. The reaction is slow. Na 2 S 2 O 3 : Sodium thiosulphate Potassium Dichromate (VI) with Ethanedioic Acid Cr 2 O 7 2- + 14H + + 3C 2 O 4 2- ⎯→ 6CO 2 + 7H 2 O + 2Cr 3+ Notes : 1. In the reaction, the orange colour of the solution turns into green. Cr 2 O 7 2- : dichromate(VI) ion (Orange) C 2 O 4 2- : ethanedioate ion (Colourless) Cr 3+ : Chromium(III) ion (green) Potassium Manganate(VII) with Ethanedioic Acid 2MnO 4 - + 16H + + 5C 2 O 4 2- ⎯→ 10CO 2 + 8H 2 O + 2Mn 2+ Notes : 1. Mn 2+ is colourless 2. In the reaction, the purple colour of the solution turns into colourless. MnO 4 - : Manganate(VII) ion (Purple) Mn 2+ : Manganese(II) ion colourless Decomposition of Hydrogen Peroxide 2H 2 O 2 - ⎯→ 2H 2 O + O 2 Catalyst: manganese(IV) oxide(MnO 2 ), Iron(III) oxide (Fe 2 O 3 ), silver (Ag) Haber Process (Manufacture Ammonia) N 2 + 3H 2 ⎯→ 2NH 3 (More detail in Form 4 Chapter 9) Contact Process(Manufacture Sulphuric Acid) 2SO 2 + O 2 ⎯→ 2SO 3 (More detail in Form 4 Chapter 9)