Chemistry P1: Practical Skills 1

CHEMISTRY KEYWORDS:

Independent Variable: Variable under investigation for which we choose different values.

Dependent Variable: Variable we measure to judge the effect of changing the independent variable.

Control Variables: Variables (other than the dependent and independent variables) that must be kept the same during an experiment.

Random Errors: Errors that are due to chance changes in the experiment or by the experimenter. They are equally likely to make the values of data too high or too low.

Systematic Errors: Errors due to data being inaccurate in a consistent way. Systematic errors are often caused by errors in the experimental procedure or equipment.

 

CHEMISTRY DEFINITIONS:

Range: Minimum and maximum values for the independent or the dependent variable.

Interval: Difference chosen between consecutive values of the independent variable.

Anomalous Result: Result that does not follow an established pattern.

Precise Results: Results in which each set of repeat readings are grouped closely together.

Accurate Results: Results that reflect the true value of a quantity.

 

SUMMARY:

In your practical examination, you will be expected to collect, record and analyse data to answer questions about the two or three activities. You will need to develop the following practical skills.

Manipulation, measurement and observation:

·       Successfully collect data and observation by setting up and carrying out experiments efficiently and safely.

·       Make precise and accurate measurements, as well as detailed observations.

·       Make decisions relating to measurements or observations, including the choice of equipment, the range and interval of measurements, and the recognition of anomalous results.

Presentation of data and observations:

·       Record data or observations in tables and display data using appropriate graphs.

·       Display calculations and reasoning in tables and logical sequences.

Analysis, conclusions and evaluation:

·       Interpret data or observations and identify sources of error, recognising systematic or random errors and working out their significance.

·       Draw conclusions based on scientific knowledge and understanding.

·       Suggest improvements that can be made to improve the quality and validity of data collected.