Formulae: past paper questions

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• Question 9May/June 2026, paper 11Multiple choice1 mark

  What is the formula of potassium oxide?

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• Question 8Oct/Nov 2025, paper 11Multiple choice1 mark

  Carbon dioxide gas reacts with aqueous calcium hydroxide to form calcium carbonate. Which equation represents this reaction?

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• Question 7Oct/Nov 2024, paper 11Multiple choice1 mark

  Metal X is in Group II of the Periodic Table. X is reacted separately with dilute sulfuric acid and with oxygen. Which row identifies the products of each reaction?

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• Question 7Oct/Nov 2023, paper 11Multiple choice1 mark

  Which equations are balanced?

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• Question 10May/June 2026, paper 11Multiple choice1 mark

  Which compound contains the greatest number of atoms in its formula?

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• Question 7Oct/Nov 2025, paper 12Multiple choice1 markHas a diagram

  The electronic configurations of atoms Q and R are shown. Q and R form an ionic compound. What is the formula of the compound?

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• Question 9Oct/Nov 2024, paper 12Multiple choice1 mark

  Which symbol equation represents the reaction between aqueous sodium hydroxide and dilute sulfuric acid?

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• Question 25Oct/Nov 2023, paper 11Multiple choice1 mark

  Zinc oxide reacts with carbon to produce zinc. Which equation represents this reaction?

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• Question 11May/June 2026, paper 11Multiple choice1 mark

  Which formula gives the $M_{\mathrm{r}}$ of lead(II) bromide?

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• Question 10Oct/Nov 2025, paper 12Multiple choice1 mark

  Which equation represents the complete combustion of butane, ${\text{C}}_4{\text{H}}_{10}$?

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• Question 9Oct/Nov 2024, paper 13Multiple choice1 mark

  Propane, ${\text{C}}_3{\text{H}}_8$, is burned in a limited amount of oxygen. Which equation represents this reaction?

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• Question 8Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  The diagram shows the structure of a molecule of ethyl ethanoate. What is the molecular formula of a molecule of ethyl ethanoate?

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• Question 7May/June 2026, paper 12Multiple choice1 markHas a diagram

  The diagram represents phosphoric acid. What is the molecular formula for phosphoric acid?

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• Question 4Oct/Nov 2025, paper 13Multiple choice1 markHas a diagram

  The electronic structures of two atoms, P and Q, are shown. P and Q combine together to form a compound. What is the type of bonding in the compound, and what is the formula of the compound?

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• Question 9Oct/Nov 2024, paper 21Multiple choice1 mark

  What is the formula of iron(III) oxide?

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• Question 7Oct/Nov 2023, paper 13Multiple choice1 markHas a diagram

  The equation represents the reaction between solid magnesium oxide and dilute hydrochloric acid to form magnesium chloride and water.

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• Question 9May/June 2026, paper 13Multiple choice1 markHas a diagram

  The diagram shows a model of an organic molecule. What is the molecular formula of this organic molecule?

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• Question 10Oct/Nov 2025, paper 13Multiple choice1 mark

  Which statement defines the term molecular formula?

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• Question 11Oct/Nov 2024, paper 22Multiple choice1 mark

  What is the empirical formula of a compound that contains $3.66\mathrm{g}$ of hydrogen, $37.8\mathrm{g}$ of phosphorus and $58.5\mathrm{g}$ of oxygen?

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• Question 8Oct/Nov 2023, paper 13Multiple choice1 mark

  What is the equation for the reaction between calcium and chlorine?

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• Question 10May/June 2026, paper 21Multiple choice1 mark

  Compound $\text{Y}$ contains $48.65\mathrm{\%}$ carbon, $8.10\mathrm{\%}$ hydrogen and $43.25\mathrm{\%}$ oxygen by mass. What is the empirical formula of compound $\text{Y}$?

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• Question 9Oct/Nov 2025, paper 21Multiple choice1 mark

  The molecular formulae of four compounds are listed. 1 $\mathrm{C}{\mathrm{H}}_4$ 2 ${\mathrm{C}}_2{\mathrm{H}}_6$ 3 ${\mathrm{C}}_3{\mathrm{H}}_8$ 4 ${\mathrm{C}}_3{\mathrm{H}}_6$ Which molecular formulae are also the empirical formulae for the compounds?

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• Question 8May/June 2026, paper 22Multiple choice1 markHas a diagram

  Which row shows the correct formulas of iron(II) bromide and zinc nitrate?

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• Question 11Oct/Nov 2025, paper 22Multiple choice1 markHas a diagram

  A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen only. The relative molecular mass, $M_r$, of the compound is 60. Which row shows the empirical formula and the molecular formula of the compound?

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• Question 8Oct/Nov 2024, paper 23Multiple choice1 mark

  Silicon(IV) oxide reacts with chlorine and carbon to form liquid silicon(IV) chloride, ${\text{SiCl}}_4$, and carbon dioxide gas. If the reaction is carried out at r.t.p., which symbol equation represents this reaction?

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• Question 7Oct/Nov 2023, paper 21Multiple choice1 markHas a diagram

  Which row shows the formulae of sodium carbonate, zinc nitrate and ammonium sulfate?

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• Question 10May/June 2026, paper 23Multiple choice1 mark

  The formula of an aluminium ion is ${\text{Al}}^{3+}$. The formula of a nitrate ion is ${\text{NO}}_3^{-}$. What is the formula of aluminium nitrate?

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• Question 9Oct/Nov 2025, paper 23Multiple choice1 mark

  Which compound has an empirical formula that is the same as its molecular formula?

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• Question 3Oct/Nov 2024, paper 32Structured11 marksHas a diagram

  The list shows some substances present in water from natural sources. dissolved oxygen calcium compounds plastics harmful microbes State which one of these substances provides essential minerals for aquatic life.

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• Question 11May/June 2026, paper 23Multiple choice1 mark

  Organic compound X has the following percentage composition by mass. $$\text{carbon }60\mathrm{\%};\text{ hydrogen }8\mathrm{\%};\text{ oxygen }32\mathrm{\%}$$ What is the empirical formula of compound X?

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