• Question: in an experiment equal-sized pieces of phosphorus were placed into each of two jars AandB. The phosphorus burst into flames and burned in both jars. It burned brighter and for a longer time in jar A than in jar B. What can you deduct that was similar about the gas in both jars?

    Asked by n0tty1997 to Daniel, Jon, Louise, Sharon on 23 Jun 2010 in Categories: .
    • Photo: Jon Copley

      Jon Copley answered on 22 Jun 2010:


      Both jars must have contained oxygen, to support the combustion. And Jar A may have contained a higher percentage of oxygen.

    • Photo: Sharon Sneddon

      Sharon Sneddon answered on 23 Jun 2010:


      HI Notty,
      As you need oxygen to cause combustion of phosphorus, both of the jars must have had o2 in them. The reason for Jar A burning longer and brighter could be down to it having more oxygen in the jar.

    • Photo: Louise Dash

      Louise Dash answered on 23 Jun 2010:


      This sounds like another homework question! Top marks for initiative in asking us if so. 😉

      There must be oxygen in both jars to support the reaction – if it was brighter and longer in jar A then I’d conclude there was a higher concentration of oxygen in that jar.

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