Potassium chlorate, KClO₃, is widely used as an oxidising agent and to make O₂(g).

1. (a)Define oxidising agent.[1]
2. (b)KClO₃(s) decomposes when heated. MnO₂(s) catalyses the exothermic decomposition reaction. Complete and label the diagram in [Figure 3.1] to show the effect of MnO₂(s) on the decomposition of KClO₃(s). enthalpy reactants progress of reaction products[2]
3. (c)When KClO₃ is heated without a catalyst, KClO₄ and KCl form. 4KClO₃ → 3KClO₄ + KCl Explain why this reaction is described as a disproportionation reaction.[1]
4. (d)(i)Use the ideal gas equation to calculate the volume, in m³, of one mole of gas at 630 K and 1.00 × 10⁵ Pa. Show your working. Give your answer to 3 significant figures.[1]
5. (d)(ii)5.00 g of C₆H₁₂O₆ reacts completely with molten KClO₃. Use your answer to (d)(i) to calculate the total volume of gas released at 630 K and 1.00 × 10⁵ Pa in this reaction. (If you were unable to answer (d)(i), use 0.0463 m³ in this question. This is not the correct answer to (d)(i).)[2]
6. (e)(i)Complete Table 3.1 to identify the number of primary, secondary and tertiary alcohol groups present in the structure shown in [Figure 3.2]. Table 3.1 type of alcohol group primary secondary tertiary number of groups[1]
7. (e)(ii)Separate samples of aqueous glucose are tested with the reagents shown in Table 3.2. Complete Table 3.2 with the observation for each reaction. Write "no reaction" if applicable. Table 3.2 reagent and conditions observation with glucose acidified KMnO₄(aq) and warm Fehling's reagent and warm alkaline I₂(aq) and warm[3]
8. (e)(iii)There are many structural isomers of C₆H₁₂O₆. Define structural isomers.[1]

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