Cambridge Pre-U Syllabus - Cambridge International Examinations

Cambridge Pre-U Syllabus
Skill Area Analysis of data and conclusions
Sub-skill
Display of calculations and reasoning
Candidates should be able to:
• show their working in calculations, and the key steps in their reasoning;
• use the correct number of significant figures for calculated quantities.
Where calculations are done, all of the key stages in the calculation should be recorded by candidates, so
that credit can be given for correctly displaying working even if the final answer is incorrect. Similarly, where
observations form the basis for logical deduction (e.g. the concentration of an unknown solution or the
identity of an unknown solute), the main steps in making the deduction should be shown. Again, where
inductive thought processes are used to build up a general prediction or to support a general theory, from
specific observations, the sequence of major steps used should be reported.
Calculated quantities should be given to the same number of significant figures as the measured quantity
that has the smallest number of significant figures. For example, if values of time and of volume of gas
collected are measured to 1 and 2 significant figures respectively, then the calculated rate should be given to
1 significant figure, but not 2 or more.
See http://www.chemsoc.org/networks/learnnet/RSCmeasurements.htm for more information on significant
figures.
Sub-skill
Description of patterns and trends
Candidates should be able to:
• use tables and graphs to draw attention to the key points in quantitative data, including the variability of
data;
• describe the patterns and trends shown by data in tables and graphs;
• describe and summarise the key points of a set of observations.
Descriptions of patterns and trends should be precise, giving quotations of figures to support the description,
and calculated values where these are appropriate.
51