Formulae, Functional Groups and Terminology

Formulae, Functional Groups and Terminology Quiz

Spec 11.1 · Cambridge IGCSE Chemistry: Quiz

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5 questions, one answer each

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  1. 1. What is the molecular formula of a compound?

    • A. The number and type of different atoms in one molecule
    • B. The simplest whole number ratio of atoms in a compound
    • C. The number of moles of each element present
    • D. The arrangement of atoms bonded together in a molecule

  2. 2. A compound contains 2 calcium ions and 2 chloride ions. What is its empirical formula?

    • A. CaCl₂
    • B. Ca₂Cl₂
    • C. CaCl
    • D. Ca₂Cl

  3. 3. Which of the following correctly shows the molecular formula for a compound with 3 carbon atoms, 8 hydrogen atoms and 2 oxygen atoms?

    • A. C₃H₈O₂
    • B. CH₃O
    • C. C₃H₈O
    • D. C₆H₁₆O₄

  4. 4. An ionic compound contains magnesium ions (Mg²⁺) and oxide ions (O²⁻) in a 1:1 ratio. What is the formula of this compound and why?

    • A. MgO₂ because magnesium forms two bonds
    • B. MgO because one Mg²⁺ ion requires one O²⁻ ion to balance charges
    • C. Mg₂O because there are two types of ion present
    • D. Mg₂O₂ because the charges must be equal

  5. 5. When sodium reacts with oxygen, sodium oxide is formed. Which of the following correctly represents the word equation and corresponding symbol equation with state symbols?

    • A. Sodium + Oxygen → Sodium oxide; 4Na(s) + O₂(g) → 2Na₂O(s)
    • B. Sodium + Oxygen → Sodium oxide; 2Na(s) + O₂(g) → Na₂O₂(s)
    • C. Sodium + Oxygen gas → Sodium oxide; 4Na(s) + O₂(g) → 2Na₂O(s)
    • D. Sodium + Oxygen → Sodium oxide; Na(s) + O(g) → NaO(s)

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