OCR A Level Chemistry A Chemistry B

OCR A Level Chemistry A (H432) Chemistry B (H433) PAG 5: Synthesis of an organic liquid Practice Exam Questions and Mark Scheme 1. Ethanol is oxidised to ethanoic acid using acidified potassium dichromate(IV) solution. The reaction is heated under reflux using the equipment shown in the diagram below. What is the reason for heating under reflux? A. to ensure even heating B. to prevent any substances escaping C. to boil the mixture at a higher temperature D. to allow efficient mixing Yo...

OCR A Level Chemistry A (H432) Chemistry B (H433) PAG 5: Synthesis of an organic liquid Practice Exam Questions and Mark Scheme 1. Ethanol is oxidised to ethanoic acid using acidified potassium dichromate(IV) solution. The reaction is heated under reflux using the equipment shown in the diagram below. What is the reason for heating under reflux? A. to ensure even heating B. to prevent any substances escaping C. to boil the mixture at a higher temperature D. to allow efficient mixing Yo...

OCR A Level Chemistry A (H432) Chemistry B (H433) PAG 5: Synthesis of an organic liquid Practice Exam Questions and Mark Scheme 1. Ethanol is oxidised to ethanoic acid using acidified potassium dichromate(IV) solution. The reaction is heated under reflux using the equipment shown in the diagram below. What is the reason for heating under reflux? A. to ensure even heating B. to prevent any substances escaping C. to boil the mixture at a higher temperature D. to allow efficient mixing Yo...

OCR A Level Chemistry A (H432) Chemistry B (H433) PAG 2: Acid-base titration Exam Questions and Mark Scheme 1. The equation for the reaction of aqueous phosphoric(V) acid, H3PO4, with aqueous sodium hydroxide, NaOH(aq) is shown below. H3PO4(aq) + 3NaOH(aq) → Na3PO4(aq) + 3H2O(l) 25.0 cm3 of a 0.200 mol dm−3 H3PO4(aq) is titrated with 0.600 mol dm−3 NaOH(aq). Which statement is correct? A. The end point occurs when 25.00 cm3 of NaOH(aq) has been added. B. The end point occurs when 75.00 cm3...

OCR A Level Chemistry A (H432) Chemistry B (H433) PAG 2: Acid-base titration Exam Questions and Mark Scheme 1. The equation for the reaction of aqueous phosphoric(V) acid, H3PO4, with aqueous sodium hydroxide, NaOH(aq) is shown below. H3PO4(aq) + 3NaOH(aq) → Na3PO4(aq) + 3H2O(l) 25.0 cm3 of a 0.200 mol dm−3 H3PO4(aq) is titrated with 0.600 mol dm−3 NaOH(aq). Which statement is correct? A. The end point occurs when 25.00 cm3 of NaOH(aq) has been added. B. The end point occurs when 75.00 cm3...