Question 4
A student does an experiment to determine a value for the enthalpy of combustion of heptane.
The figure below shows some of the apparatus used.
(a) Design a table to record all the readings necessary to determine an experimental value for the enthalpy of combustion for heptane in this experiment.
(2)
(b) The student considered using a glass beaker on a tripod and gauze instead of the clamped copper calorimeter.
Suggest two disadvantages of using a glass beaker on a tripod and gauze.
(2)
(c) Suggest two reasons why the value of enthalpy of combustion from this experiment is less exothermic than a data book value.
(2)
(d) Suggest one addition to this apparatus that would improve the accuracy of the enthalpy value obtained.
(1)
(Total 7 marks)