11. Organic chemistry
A section of Chemistry, 0620
Listing 10 of 1367 questions
Many organic compounds contain carbon, hydrogen and oxygen only. An organic compound R has the following composition by mass. C, 69.77%; H, 11.63%; O, 18.60% Calculate the empirical formula of compound R.  empirical formula = Compound S has the empirical formula CH2O and a relative molecular mass of 60. Calculate the molecular formula of compound S.  molecular formula = Compounds T and V have the same molecular formula, C3H6O2. ● Compound T is an ester. ● Compound V contains a –COOH functional group. State the name given to compounds with the same molecular formula but different structures. Name the homologous series that V is a member of. Draw a structure of compound T. Show all of the atoms and all of the bonds. Name compound T. name  Draw the structure of compound V. Show all of the atoms and all of the bonds. Name compound V. name  Ethanol can be produced from long chain alkanes such as decane, C10H22, in a two-step process. step 1 step 2 decane ethene ethanol For each of the two steps: ● name the type of chemical reaction that occurs ● write a chemical equation. step 1: decane to ethene type of reaction chemical equation step 2: ethene to ethanol type of reaction chemical equation  
0620_s21_qp_43
THEORY
2021
Paper 4, Variant 3
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Ethanol is made industrially by the reaction of ethene with steam. The reaction occurs at a temperature of 300 °C and a pressure of 60 atmospheres. C2H4+ H2OC2H5OHA catalyst is used in this reaction. The forward reaction is exothermic. State what is meant by the term catalyst. Complete the table using only the words increases, decreases or no change. effect on the rate of the forward reaction effect on the equilibrium yield of C2H5OHincreasing the temperature decreasing the pressure  Ethanol is a member of the alcohol homologous series. Members of the same homologous series have the same general formula. State the general formula of alcohols. State two general characteristics, other than the same general formula, of all homologous series.  One alcohol containing three carbon atoms is propan-1-ol. Draw the structure of one other alcohol containing three carbon atoms. Show all of the atoms and all of the bonds. Name the alcohol you have drawn. name  When alcohols react with carboxylic acids, esters are produced. The structure of ester X is shown. O O H C H H C H H C H H C H H H H H C C Name ester X. Give the name of the alcohol and the carboxylic acid that react together to produce esterX. alcohol carboxylic acid  Ester Y has the following composition by mass: C, 58.82%; H, 9.80%; O, 31.37%. Calculate the empirical formula of ester Y.  empirical formula = Ester Z has the empirical formula C3H6O and a relative molecular mass of 116. Calculate the molecular formula of ester Z.  molecular formula = 
0620_s22_qp_43
THEORY
2022
Paper 4, Variant 3
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Fig.7.1 shows the displayed formula of mesaconicacid. C C C H O H C O H C O H H H O On Fig.7.1 draw a circle around one carboxylic acid functional group. Deduce the molecular formula of mesaconicacid. Mesaconicacid is a colourless compound. Describe the colour change when excess mesaconicacid is added to aqueous bromine. from to ������������������������������������������������������������� Ethanoicacid belongs to the homologous series of carboxylic acids. Define the term homologous series. Complete the word equation for the reaction of ethanoicacid with magnesium. ethanoic acid + magnesium +  Ethanoicacid reacts with ethanol. The organic product has the molecular formula C4H8O2. Complete Table7.1 to calculate the relative molecular mass of C4H8O2. Table 7.1 atom number of atoms relative atomic mass carbon 4 × 12 = 48 hydrogen oxygen  relative molecular mass = Ethanol can be manufactured by fermentation. Complete the word equation for one other method of manufacturing ethanol. + → ethanol 
0620_s23_qp_31
THEORY
2023
Paper 3, Variant 1
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