A-LevelChemistryReaction kineticsFeb/Mar 2025Paper 1 Q91 Mark
An aqueous solution of hydrogen peroxide is placed in a flask and decomposes, as shown. 2H2O2(aq) → 2H2O(l) + O2(g) The total volume of oxygen gas evolved is 180 cm³ after 90 seconds, measured under room conditions. The rate of the reaction is calculated using the equation shown. rate = change in moles of H2O2 / time What is the average rate of the reaction, measured in mol min⁻¹, over the duration of the experiment?
A8.33 × 10⁻⁵
B1.67 x 10⁻⁴
C0.0050
D0.010
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