Sub-topic 1
2026 · National Preliminary
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Empirical formula of an oxide from percent composition and atomic mass
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Sub-topic 2
2026 · National Preliminary
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Molecular formula from percent composition and a given molar mass
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Sub-topic 3
2026 · National One-Eighth
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Molecular formula from percent composition and a given molar mass
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Sub-topic 4
2026 · National Quarterfinal
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Empirical formula of a hydrocarbon from the mass of carbon dioxide produced on combustion
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Sub-topic 5
2026 · National Quarterfinal
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Molecular formula of an oxide of nitrogen from percentage composition and molar mass
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Sub-topic 6
2026 · National Quarterfinal
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Mass of an element present in a sample from its percentage composition by mass
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Sub-topic 7
2024 · National Preliminary
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Percentage composition by mass in a compound
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Sub-topic 8
2026 · National One-Eighth
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Percentage composition by mass in a compound
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Sub-topic 9
2018 · National One-Eighth
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Percentage yield and mass obtainable at a given yield
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Sub-topic 10
2018 · National Quarterfinal
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Empirical formula from percentage composition
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Sub-topic 11
2025 · National Preliminary
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Empirical formula from percentage composition
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Sub-topic 12
2021 · National Preliminary
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Identifying a compound from a percentage mass ratio
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Sub-topic 13
2026 · National Preliminary
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Percentage composition by mass in a compound
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Sub-topic 14
2024 · National One-Eighth
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Percentage yield from a given mass of product
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Sub-topic 15
2024 · National One-Eighth
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Molecular formula of a compound from percentage composition
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Sub-topic 16
2026 · National Final
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Percentage composition of a carbonate/oxide mixture from mass lost on heating
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Sub-topic 17
2025 · National Preliminary
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Molecular formula from a compound's mass and moles, given its empirical formula
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Sub-topic 18
2025 · National One-Eighth
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Mass of pure solute in a solution from its percentage by mass and density
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Sub-topic 19
2025 · National One-Eighth
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Mass of pure solute in a solution from its percentage by mass and density
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Sub-topic 20
2003 · National Semifinal
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Percentage composition by mass of an element in a compound
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Sub-topic 21
2003 · National Semifinal
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Percentage composition by mass of an element in a compound
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Sub-topic 22
2014 · National Quarterfinal
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Mass of ethanoic acid obtainable from ethanol at a given percentage yield
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Sub-topic 23
2021 · National Preliminary
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Determining a molecular formula (c9h8o4) from molar mass and the mass of carbon present
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Sub-topic 24
2022 · National Preliminary
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Total atoms in a molecular formula scaled up from an empirical formula via a known atom count
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Sub-topic 25
2022 · National Preliminary
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Percentage by mass of oxygen in methanol (ch4o)
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Sub-topic 26
2022 · National Preliminary
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Empirical formula of a hydrocarbon from its percentage carbon by mass
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Sub-topic 27
2022 · National Preliminary
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Percentage by mass of oxygen in kclo4
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Sub-topic 28
2022 · National Preliminary
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Percentage by mass of manganese in mn2o7
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Sub-topic 29
2022 · National Preliminary
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Percentage by mass of chromium in sodium dichromate
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Sub-topic 30
2023 · National One-Eighth
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Empirical formula tg4 from masses and atomic masses of two elements
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