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Week 1

Two bottles containing different white crystals have lost their labels. The Science teacher says that one of them contains potassium chloride (KCl) and the other glucose (C6H12O6).

Using your knowledge of Chemistry, describe how you would decide which bottle is which.       (3)


You should have recognised that one of the compounds has Ionic bonding and the other has covalent. When being asked to compare two compounds, this should be the first thing you check, as the way in which atoms join together will determine the properties of that compound. 

Your answer could have included 

  • Definition of Ionic and Covalent 
  • Conductivity, solubility, state at room temp (Difference between molecular and network)

Other possibilities include:

Salt formation – neutralisation reactions

Energy released from fuels