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Ethanoic acid and propanone, CH3COCH3, each contain a C=O group, and their molar masses are close. (i) Considering the strongest intermolecular forces in each liquid, explain why propanone boils at a much lower temperature than ethanoic acid.…
Ethanoic acid acts as a weak monoprotic acid in aqueous solution. At 298 K its acid dissociation constant is Ka = 1.74 × 10−5 mol dm−3. (i) 2.00 dm3 of an ethanoic acid solution was prepared. A 25.0 cm3…
Heat treatment at 90 °C is used to destroy spoilage micro-organisms in pineapple juice. The concentration of vitamin C was measured over 56 days in untreated juice and in heat-treated juice from the same batch. (i) Identify the dependent variable in this…
Ultraviolet (UV) light is being investigated as a way of killing micro-organisms in juice without heating it, so that less vitamin C is lost. The absorption spectrum of a dilute aqueous solution of sorbic acid, a preservative that is added to some bottled…
The concentration of vitamin C and the pH of five fruit juices were measured. Use the data to deduce whether pH and the concentration of vitamin C are correlated, giving a reason.
The vitamin C content of a juice can be found by titrating a sample against a standard iodine solution. Starch is used as the indicator: it forms a dark blue-black complex with the first excess of iodine once all the vitamin C has reacted.…
Liquid octane burns completely in oxygen to give carbon dioxide and liquid water. C8H18(l) + O2(g) → CO2(g) + H2O(l) What is the C8H18 : O2 ratio when the equation is balanced using the smallest whole-number coefficients? A. 1 : 12 B. 1 :…
Outline the meaning of the term “homologous series”, with reference to the carboxylic acids.
Calculate the mass percentage of oxygen in ethanoic acid.
Ethanoic acid and propanone, CH3COCH3, both contain a carbonyl group and have similar molar masses. (i) Explain, in terms of the strongest intermolecular forces present in each liquid, why propanone boils at a much lower temperature than ethanoic acid.…