The diagram below shows a molecule of maltose.    
   

   
This molecule can be broken into two glucose molecules by a chemical reaction    
(a) (i) What type of reaction would this be    
    Hydrolysis   (1)
  (ii) What substance would need to be added for this reaction to proceed    
    Water   (1)
  (iii) Draw below one of the glucose molecules that would be formed by this reaction    
   

  (1)
(b)   Describe how you would perform a test to indicate that a substance contained sucrose and not glucose    
   

First show glucose (a monosaccharide) is not present

  • Add Benedicts solution
  • Blue colour when heated shows no glucose present

Then show a maltose (a disaccharide) is present

  • Warm a sample with dilute HCl
  • Neutralise
  • Add Benedicts solution
  • Red/Brown colour on heating shows disaccharide present

NOTE score a max of 2 bullet points in each section

  (4)

 

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