HIGH SCHOOL CHEMISTRY MASTERBANK
HIGH SCHOOL CHEMISTRY
MASTER BANK
Final-Week Revision Edition — FINAL EXAM HACKS
HOW TO USE THIS IN YOUR FINAL WEEK
This is not a textbook — it's a compression of HIGH SCHOOL chemistry
organized by topic cluster).
For each cluster you get:
• Core facts — the non-negotiable content
• Key equations / formulae
• Worked examples — including the calculation style the
examiner actually asks
• Exam traps — where students lose marks even when they "know"
the topic
Suggested final-week rhythm: 2 clusters/day in the morning (recall), past
paper questions on those clusters in the afternoon, traps list before bed.
A day-by-day plan is at the very end.
PART 0: QUICK-REFERENCE SHEET
(memorize this page cold)
Constants
, HIGH SCHOOL CHEMISTRY MASTERBANK
• Molar gas volume at s.t.p. = 22,400 cm³ (22.4 L); at r.t.p. = 24,000
cm³ (24 L)
• Avogadro's number = 6.02 × 10²³ particles/mole
• 1 Faraday = 96,500 coulombs (charge on 1 mole of electrons)
• Standard conditions: s.t.p. = 0°C (273K), 760 mmHg; r.t.p. = 25°C
(298K), 760mmHg
Master formulae
• Moles = Mass (g) ÷ Molar mass (RFM/RMM)
• Moles = Volume (dm³) ÷ Molar volume (22.4 at s.t.p., or 24 at
r.t.p.)
• Moles = Concentration (mol/dm³) × Volume (dm³)
• Concentration (g/dm³) = Concentration (mol/dm³) × Molar mass
• Q = It (charge = current × time), then moles of electrons = Q ÷
96500
• % yield = (actual yield ÷ theoretical yield) × 100
• % purity = (mass of pure substance ÷ mass of impure sample) ×
100
• Rf value = distance moved by solute ÷ distance moved by solvent
• Relative atomic mass (isotopes) = Σ(isotope mass × %
abundance) ÷ 100
Common colour changes to know cold
• Litmus: red in acid, blue in base
• Phenolphthalein: colourless in acid, pink in base
• Methyl orange: red/pink in acid, yellow in base
• Anhydrous CuSO₄: white → blue (test for water)
• Anhydrous CoCl₂ paper: blue → pink (test for water)
• Lime water: turns milky/cloudy with CO₂ (excess CO₂ clears it
again — forms soluble Ca(HCO₃)₂)
• Acidified potassium dichromate(VI): orange → green (reduction,
e.g. by SO₂, or ethanol → ethanoic acid)
• Acidified/alkaline KMnO₄: purple → colourless (reducing agents,
e.g. SO₂, Fe²⁺)
• Starch–iodine: blue-black (test for starch/iodine)
• Brown ring test: brown ring = nitrate(V) ion (NO₃⁻)
, HIGH SCHOOL CHEMISTRY MASTERBANK
A. MATTER, CLASSIFICATION &
SEPARATION TECHNIQUES
Core facts
• Matter exists as solid, liquid, gas — particle theory explains state
changes via particle arrangement, energy, and movement.
• Mixtures = homogeneous (uniform, one phase, e.g. salt solution)
or heterogeneous (e.g. sand + water).
• Separation technique depends on the property difference:
○ Filtration — insoluble solid from liquid
○ Evaporation — soluble solid from solution (destroys the
solvent)
○ Crystallization — soluble solid, preserves the compound's
crystal form, used when substance decomposes on heating
too strongly
○ Simple distillation — solvent from solution (e.g. water from
salt solution)
○ Fractional distillation — liquids with different but close
boiling points (e.g. ethanol/water, crude oil fractions, liquid
air)
○ Chromatography — separating dissolved substances/dyes
by differential movement on a medium
○ Sublimation — separating a solid that sublimes (e.g.
iodine, ammonium chloride) from one that doesn't
○ Decantation — pouring off liquid from a settled solid
○ Separating funnel — two immiscible liquids (different
densities)
○ Magnetic separation — one component magnetic (e.g. iron
filings from sulphur)
Worked examples
1. Separate a mixture of sand, salt, and water. → Filter (removes
sand) → Evaporate/distil filtrate: simple distillation recovers pure
water AND leaves salt behind, OR evaporate to dryness to just
recover salt crystals.
2. Separate ethanol (b.p. 78°C) from water (b.p. 100°C). →
Fractional distillation, using a fractionating column; ethanol distils
HIGH SCHOOL CHEMISTRY
MASTER BANK
Final-Week Revision Edition — FINAL EXAM HACKS
HOW TO USE THIS IN YOUR FINAL WEEK
This is not a textbook — it's a compression of HIGH SCHOOL chemistry
organized by topic cluster).
For each cluster you get:
• Core facts — the non-negotiable content
• Key equations / formulae
• Worked examples — including the calculation style the
examiner actually asks
• Exam traps — where students lose marks even when they "know"
the topic
Suggested final-week rhythm: 2 clusters/day in the morning (recall), past
paper questions on those clusters in the afternoon, traps list before bed.
A day-by-day plan is at the very end.
PART 0: QUICK-REFERENCE SHEET
(memorize this page cold)
Constants
, HIGH SCHOOL CHEMISTRY MASTERBANK
• Molar gas volume at s.t.p. = 22,400 cm³ (22.4 L); at r.t.p. = 24,000
cm³ (24 L)
• Avogadro's number = 6.02 × 10²³ particles/mole
• 1 Faraday = 96,500 coulombs (charge on 1 mole of electrons)
• Standard conditions: s.t.p. = 0°C (273K), 760 mmHg; r.t.p. = 25°C
(298K), 760mmHg
Master formulae
• Moles = Mass (g) ÷ Molar mass (RFM/RMM)
• Moles = Volume (dm³) ÷ Molar volume (22.4 at s.t.p., or 24 at
r.t.p.)
• Moles = Concentration (mol/dm³) × Volume (dm³)
• Concentration (g/dm³) = Concentration (mol/dm³) × Molar mass
• Q = It (charge = current × time), then moles of electrons = Q ÷
96500
• % yield = (actual yield ÷ theoretical yield) × 100
• % purity = (mass of pure substance ÷ mass of impure sample) ×
100
• Rf value = distance moved by solute ÷ distance moved by solvent
• Relative atomic mass (isotopes) = Σ(isotope mass × %
abundance) ÷ 100
Common colour changes to know cold
• Litmus: red in acid, blue in base
• Phenolphthalein: colourless in acid, pink in base
• Methyl orange: red/pink in acid, yellow in base
• Anhydrous CuSO₄: white → blue (test for water)
• Anhydrous CoCl₂ paper: blue → pink (test for water)
• Lime water: turns milky/cloudy with CO₂ (excess CO₂ clears it
again — forms soluble Ca(HCO₃)₂)
• Acidified potassium dichromate(VI): orange → green (reduction,
e.g. by SO₂, or ethanol → ethanoic acid)
• Acidified/alkaline KMnO₄: purple → colourless (reducing agents,
e.g. SO₂, Fe²⁺)
• Starch–iodine: blue-black (test for starch/iodine)
• Brown ring test: brown ring = nitrate(V) ion (NO₃⁻)
, HIGH SCHOOL CHEMISTRY MASTERBANK
A. MATTER, CLASSIFICATION &
SEPARATION TECHNIQUES
Core facts
• Matter exists as solid, liquid, gas — particle theory explains state
changes via particle arrangement, energy, and movement.
• Mixtures = homogeneous (uniform, one phase, e.g. salt solution)
or heterogeneous (e.g. sand + water).
• Separation technique depends on the property difference:
○ Filtration — insoluble solid from liquid
○ Evaporation — soluble solid from solution (destroys the
solvent)
○ Crystallization — soluble solid, preserves the compound's
crystal form, used when substance decomposes on heating
too strongly
○ Simple distillation — solvent from solution (e.g. water from
salt solution)
○ Fractional distillation — liquids with different but close
boiling points (e.g. ethanol/water, crude oil fractions, liquid
air)
○ Chromatography — separating dissolved substances/dyes
by differential movement on a medium
○ Sublimation — separating a solid that sublimes (e.g.
iodine, ammonium chloride) from one that doesn't
○ Decantation — pouring off liquid from a settled solid
○ Separating funnel — two immiscible liquids (different
densities)
○ Magnetic separation — one component magnetic (e.g. iron
filings from sulphur)
Worked examples
1. Separate a mixture of sand, salt, and water. → Filter (removes
sand) → Evaporate/distil filtrate: simple distillation recovers pure
water AND leaves salt behind, OR evaporate to dryness to just
recover salt crystals.
2. Separate ethanol (b.p. 78°C) from water (b.p. 100°C). →
Fractional distillation, using a fractionating column; ethanol distils
