Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
171–180 of 335 · Normal
Question 171
3 marks · Normal
Answer and see the solution →The hydration of ethene is used industrially to make ethanol from ethene and steam. Write a balanced chemical equation for this reaction. Give two reasons why converting ethene to ethanol by hydration is important for industry.
Question 172
4 marks · Normal
Answer and see the solution →The table shows two important reactions of ethene.
Addition reactions of ethene Name of reaction Reactants Product Hydrogenation Ethene (), hydrogen () Hydration Ethene (), water (steam, ) (a)Complete the table by writing the balanced symbol equation for each reaction. Write the correct chemical formula for each product.
(i)[1 mark]Hydrogenation of ethene:
(ii)[2 marks]Hydration of ethene:
(b)State the names of the organic products formed in the two reactions above.
(i)[0.5 marks]Product from hydrogenation:
(ii)[0.5 marks]Product from hydration:
Question 173
6 marks · Normal
Answer and see the solution →(a)[1 mark]Describe what is observed when bromine water is added to an alkene and the mixture is shaken.
(b)[2 marks]Write a balanced chemical equation for the reaction between but-2-ene and bromine.
(c)[1 mark]Explain why the reaction you wrote in part b is called an addition reaction.
(d)[1 mark]Describe what you would see if bromine water is added to hexane instead of but-2-ene and the mixture is shaken.
(e)[1 mark]State the difference between complete combustion and addition reactions of alkenes.
Question 174
6 marks · Normal
Answer and see the solution →(a)[2 marks]Combust ethene in air. Write the balanced symbol equation for this reaction.
(b)[2 marks]Describe in detail how you would use bromine water to distinguish between ethene and ethane.
(c)[2 marks]Explain why only one of these gases decolourises bromine water.
Question 175
6 marks · Normal
Answer and see the solution →(a)[2 marks]A student finds that a colourless, flammable liquid decolourises bromine water and burns with a smoky flame.
Explain what these two observations tell you about the type of hydrocarbon present.
(b)[2 marks]The student tests another liquid and observes that it does not decolourise bromine water and burns with a clean flame.
What type of hydrocarbon is this? Explain your reasoning.
(c)[2 marks]Write the displayed formula for but-1-ene, the alkene that would show these observations.
Question 176
6 marks · Normal
Answer and see the solution →Hex-2-ene, C6H12, is a liquid alkene. A sample is tested and burned under different conditions.
(a)[1 mark]State what is meant by an 'addition reaction' in the context of alkenes.
(b)[2 marks]Write a balanced chemical equation for the complete combustion of hex-2-ene, C6H12.
(c)[1 mark]Draw the structural formula of the compound formed when hex-2-ene reacts with bromine.
(d)[2 marks]Describe how you would test a sample of hex-2-ene using bromine water, and state the expected observation.
Question 177
2 marks · Normal
Answer and see the solution →State the number of carbon atoms in the molecules of:
(a)[1 mark]methanol
(b)[1 mark]butan-1-ol
Question 178
4 marks · Normal
Answer and see the solution →Name each alcohol below using IUPAC conventions.
(a)[1 mark]An alcohol with the molecular formula C2H6O and the structural formula CH3CH2OH.
(b)[1 mark]An alcohol with the molecular formula C3H8O where the -OH group is attached to the second carbon atom.
(c)[1 mark]An alcohol with four carbon atoms and the -OH group attached to the first carbon atom.
(d)[1 mark]State another acceptable name that could be used for butan-1-ol in an exam.
Question 179
3 marks · Normal
Answer and see the solution →Explain why both 'propanol' and 'propan-2-ol' could be correct names for different alcohol compounds. Use the structure and position of the –OH group in your answer.
Question 180
4 marks · Normal
Answer and see the solution →Table 1 shows information about some alcohols.
Table 1. Formulae of some alcohols Name Molecular formula Structural formula methanol CH4O CH3OH ethanol C2H6O CH3CH2OH ? C3H8O CH3CH2CH2OH butan-2-ol C4H10O CH3CHOHCH2CH3 (a)[1 mark]Name the alcohol in Table 1 with the molecular formula C3H8O and the structural formula CH3CH2CH2OH.
(b)[1 mark]How many carbon atoms are present in ethanol?
(c)[2 marks]Write the displayed formula for methanol, showing all bonds.