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11. Organic chemistry
A section of Chemistry, 0620
Listing 10 of 1367 questions
A student adds an aqueous solution of sodium hydroxide to an aqueous solution of ethanoic acid. She measures the temperature before and after the addition of sodium hydroxide. ethanoic acid solution 18 °C 22 °C sodium hydroxide solution at 18 °C Explain how this experiment shows that the reaction is exothermic. Complete the formula of ethanoic acid showing all atoms and bonds. H C C H H The product of the reaction is a salt called sodium ethanoate. Describe how you would prepare pure, dry crystals of sodium ethanoate from a solution of sodium ethanoate in water. Ethanoic acid belongs to the carboxylic acid homologous series. Which two of the following statements describes the members of the same homologous series? Tick two boxes. They have the same physical properties. They have different functional groups. They have similar chemical properties. They are all inorganic chemicals. They have the same functional group. Ethanoic acid has similar properties to hydrochloric acid. What would be observed when a small piece of magnesium is added to aqueous ethanoic acid?
0620_s15_qp_23
THEORY
2015
Paper 2, Variant 3
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Biogas is made by fermenting animal and vegetable waste. The table shows the percentage composition of the gases present in a sample of biogas. substance present percentage present in biogas carbon dioxide hydrogen 1.0 methane 61.5 nitrogen 8.5 water vapour 2.2 other substances 0.1 total 100.0 Deduce the percentage of carbondioxide present in this sample of biogas. During the fermentation, carbon dioxide reacts with hydrogen to produce methane and water. Complete the chemical equation for this reaction. CO2 + H2 CH4 + H2O Methane and ethane are in the same homologous series. What is meant by the term homologous series? Draw a dot-and-cross diagram to show the electron arrangement in a molecule of methane, CH4. Show outer shell electrons only.  Helium and hydrogen can both be used to fill balloons. Suggest one advantage of using helium rather than hydrogen to fill balloons. The biogas fermentation mixture contains a small amount of compoundC. The structure of compoundC is shown. C H C H H H H H H H H O H C C C S S C On the structure shown, draw a circle around a functional group which reacts with aqueousbromine. How many different types of atoms are present in compoundC? Ethanol is produced by fermentation of a mixture of plant sugars. Describe how ethanol can be separated from the rest of the fermentation mixture by fractional distillation. In your answer: ● ● describe how to do the fractional distillation ● ● explain how ethanol is separated from the rest of the fermentation mixture using fractional distillation. 
0620_w19_qp_32
THEORY
2019
Paper 3, Variant 2
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Ethanol is manufactured from glucose, C6H12O6, by fermentation according to the following equation. C6H12O6 → 2C2H5OH + 2CO2 State the conditions required for this reaction. In an experiment, 30.0 g of glucose was fermented. Calculate the number of moles of glucose in 30.0 g. mol Calculate the maximum mass of ethanol that could be obtained from 30.0 g of glucose. g Calculate the volume of carbon dioxide at room temperature and pressure that can be obtained from 30.0 g of glucose. dm3 Ethanol can also be manufactured from ethene. Name the raw material which is the source of ethene. Write a balanced equation for the manufacture of ethanol from ethene.
0620_m15_qp_32
THEORY
2015
Paper 3, Variant 2
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