Gassy information

Do each of these scenarios allow you fully to deduce the required facts about the reactants?
Exploring and noticing Working systematically Conjecturing and generalising Visualising and representing Reasoning, convincing and proving
Being curious Being resourceful Being resilient Being collaborative


 


In designing experiments it is important to be sure that the data measured will be sufficient to reach a desired conclusion. In each of the following situations, will the information provided always, sometimes or never be sufficient to determine the required information about the reactants? Provide a clear analysis in each case.

 

  • A gaseous alcohol is completely combusted with an excess of oxygen at $400$K. The change in volume of gasses is measured. Can I determine the formula of the alcohol?
  • A gaseous hydrocarbon is completely combusted with an excess of oxygen at $400$K. The change in volume of gasses is measured. The system is then cooled to $273$K and the change in volume of gasses measured. Can I determine the molecular formula of the hydrocarbon?
  • A quantity of gas is contained in a piston which is configured to exert a fixed pressure on the gas. The volume of gas is measured at two different temperatures. Can I determine the number of moles of the gas present?
  • A gaseous hydrocarbon with known molecular formula is combusted with an insufficient supply of oxygen, resulting in a mixture of H$_2$O, CO and CO$_2$, with no oxygen present. The initial volume of hydrocarbon gas and the change in total volume of gas are measured. Can I determine the initial volume of oxygen?