Sub-topic 1
2026 · National One-Eighth
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Sigma and pi bond counting in hydrocarbons using total-atom and bond-order shortcuts
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Sub-topic 2
2026 · National Preliminary
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Factors affecting the likelihood of ionic bond formation: electronegativity, ionization energy and electron affinity
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Sub-topic 3
2026 · National Preliminary
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Enthalpy change of reaction from bond enthalpies (hess's law)
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Sub-topic 4
2026 · National Semifinal
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Enthalpy change of reaction from bond enthalpies (hess's law)
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Sub-topic 5
2026 · National Preliminary
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Enthalpy change of reaction from bond enthalpies (hess's law)
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Sub-topic 6
2026 · National Preliminary
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Enthalpy change of reaction from bond enthalpies (hess's law)
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Sub-topic 7
2025 · National Semifinal
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Deducing an element's ionic charge and other compound formulas from a given phosphate formula
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Sub-topic 8
2023 · National Preliminary
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Standard enthalpy of combustion from standard enthalpies of formation (hess's law)
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Sub-topic 9
2026 · National Quarterfinal
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Standard enthalpy of combustion from standard enthalpies of formation (hess's law)
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Sub-topic 10
2026 · National Quarterfinal
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Enthalpy change for combustion of a given mass from the molar enthalpy of combustion
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Sub-topic 11
2026 · National Quarterfinal
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Total enthalpy of bonds formed in the product of a hydrogenation reaction from bond energies
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Sub-topic 12
2012 · National Preliminary
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Counting sigma and pi bonds in an alkyne
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Sub-topic 13
2026 · National One-Eighth
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Counting sigma and pi bonds in an alkyne
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Sub-topic 14
2018 · National Preliminary
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Enthalpy of polymerisation from bond energies
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Sub-topic 15
2018 · National Preliminary
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Vsepr molecular shape of so2
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Sub-topic 16
2021 · National Preliminary
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Predicting an ionic formula from valence electron counts
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Sub-topic 17
2021 · National Preliminary
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Predicting an ionic formula from valence electron counts
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Sub-topic 18
2021 · National Preliminary
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Hydrogen bonding and relative boiling points (true/false)
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Sub-topic 19
2021 · National Preliminary
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Requirements for covalent bond formation (true/false)
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Sub-topic 20
2017 · National One-Eighth
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When hydrogen bonding does and doesn't occur (true/false)
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Sub-topic 21
2021 · National Preliminary
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When hydrogen bonding does and doesn't occur (true/false)
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Sub-topic 22
2026 · National Preliminary
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Basic concepts of ion formation and ionic crystals (true/false)
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Sub-topic 23
2026 · National Preliminary
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Basic concepts of ion formation and ionic crystals (true/false)
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Sub-topic 24
2024 · National One-Eighth
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Naming enthalpies of combustion, vaporization and atomization
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Sub-topic 25
2017 · National Quarterfinal
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Standard enthalpy of formation of a hydrocarbon from combustion and formation data (hess's law)
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Sub-topic 26
2022 · National Final
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Standard enthalpy of formation of a hydrocarbon from combustion and formation data (hess's law)
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Sub-topic 27
2017 · National Quarterfinal
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Vsepr shapes of covalent fluorides from central-atom electron domains (linear, bent, planar, pyramidal)
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Sub-topic 28
2023 · National Preliminary
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Vsepr shapes of covalent fluorides from central-atom electron domains (linear, bent, planar, pyramidal)
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Sub-topic 29
2017 · National One-Eighth
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Special hydrogen bonding in ethanoic acid (dimer formation) and properties of water arising from hydrogen bonding
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Sub-topic 30
2017 · National Quarterfinal
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Comparing the stability of two structural isomers via combustion enthalpies from bond energies
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Sub-topic 31
2024 · Regional Championship
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Properties and strength of metallic bonding (true/false)
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Sub-topic 32
2026 · National One-Eighth
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Vapor pressure, boiling point and relative intermolecular force strength between two liquids (true/false)
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Sub-topic 33
2026 · National Preliminary
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Enthalpy as a state function: cyclic processes and hess's law applicability (true/false)
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Sub-topic 34
2026 · National Preliminary
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Riddle: zwitterion, a dipolar ion with both positive and negative charges
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Sub-topic 35
2025 · National One-Eighth
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Bonding and hybridization in graphite, silicon dioxide and graphene (true/false)
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Sub-topic 36
2026 · National Preliminary
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Bonding and hybridization in graphite, silicon dioxide and graphene (true/false)
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Sub-topic 37
2025 · National Preliminary
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Heat released from the enthalpy of solution and mass of a dissolved salt
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Sub-topic 38
2023 · National Preliminary
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Riddle: ice, less dense than liquid water
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Sub-topic 39
2023 · National Preliminary
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Molecular polarity of boron trifluoride, silicon tetrafluoride, and phosphorus trichloride (true/false)
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Sub-topic 40
2003 · National Semifinal
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Hardness of diamond from its covalent tetrahedral lattice
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Sub-topic 41
2012 · National Preliminary
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The carbon-oxygen double bond (sigma + pi) in alkanones
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Sub-topic 42
2003 · National Semifinal
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Softness of graphite from its layered structure and weak interlayer forces
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Sub-topic 43
2013 · National Preliminary
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Predicting bond type between two elements from their atomic numbers (metal + nonmetal)
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Sub-topic 44
2013 · National Preliminary
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Predicting bond type between two elements from their atomic numbers (nonmetal + metalloid)
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Sub-topic 45
2013 · National Preliminary
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Predicting bond type between two elements from their atomic numbers (nonmetal + nonmetal)
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Sub-topic 46
2013 · National Preliminary
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Mgo is ionic while mgh2 shows mixed ionic/covalent character (true/false)
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Sub-topic 47
2013 · National Preliminary
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Non-metal oxides tend to be covalent (true/false)
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Sub-topic 48
2013 · National Preliminary
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The carbon-silicon bond is covalent (true/false)
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Sub-topic 49
2013 · National Preliminary
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Hydrogen halides in the pure state are covalent, not ionic (true/false)
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Sub-topic 50
2018 · National Preliminary
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Inductive effect of methyl groups increasing arsenic's electron-donating ability
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Sub-topic 51
2018 · National Preliminary
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The c-c triple bond is shorter than the c-c double bond, not the reverse (true/false)
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Sub-topic 52
2018 · National Preliminary
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C-n bonds in amines are shorter than c-c bonds (true/false)
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Sub-topic 53
2018 · National Preliminary
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The so2 molecule has two pi bonds between sulfur and oxygen (true/false)
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Sub-topic 54
2019 · National Preliminary
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H-n-h bond angle in ammonia versus the ideal tetrahedral angle
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Sub-topic 55
2021 · National Preliminary
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Predicting the formula y2x3 from outer-shell electron counts of 6 and 3
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Sub-topic 56
2021 · National Quarterfinal
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Sp² hybridization of the carbon orbital in the bicarbonate ion hco3-
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Sub-topic 57
2021 · National Semifinal
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Counting pi bonds in sulfuric acid from its two s=o double bonds
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Sub-topic 58
2022 · National Preliminary
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True or false: the simplest alkyne has two pi bonds
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Sub-topic 59
2022 · National Preliminary
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True or false: the simplest alkyne has three sigma bonds
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Sub-topic 60
2022 · National Preliminary
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True or false: the simplest alkene has four sigma bonds
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Sub-topic 61
2022 · National Preliminary
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The o-h bonds in water are polar covalent bonds
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Sub-topic 62
2022 · National One-Eighth
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True or false: ethene has four sigma and two pi bonds
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Sub-topic 63
2022 · National One-Eighth
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True or false: chloroethene has one pi bond and five sigma bonds
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Sub-topic 64
2022 · National One-Eighth
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True or false: methanal has one pi bond and three sigma bonds
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Sub-topic 65
2022 · National One-Eighth
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True or false: bromide ion has higher polarizability than chloride ion
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Sub-topic 66
2022 · National One-Eighth
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True or false: oxide ion has higher polarizability than sulfide ion
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Sub-topic 67
2022 · National One-Eighth
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True or false: oxide ion has higher polarizability than fluoride ion
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