A-LevelChemistryChemical periodicity9701/12 · Feb/Mar 2019 · Q131 Mark

A solid Period 3 element, Q, is reacted with oxygen gas. Compound R is formed. When R is added to water the pH decreases. What could be the empirical formula of R?

AQ₂O₄

BQ₂O₅

CQ₄O₁₀

DQ₅O₂

✓ Correct answer

B: Q₂O₅

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Topic: Chemical periodicity, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Feb/Mar 2019 Paper 1 Variant 2, question 13.

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