Ch21 Experimental Design and Separation Techniques Flashcards
Define accuracy:
How close the value is to the true value
Define precision:
The degree to which repeat measurements are considered (close to each other)
Define resolution:
The smallest division on the instrument
Example this could be 1mm on a ruler or 0.1g on a balance
Define calibration:
The process of checking that the device gives accurate values by using it to read samples with known values
Define repeatability:
Where an experiment (or series of experiments) can be repeated using the same method and obtain reproducible (similar) results
Define control variable:
A variable that is kept the same during an investigation
Define independent variable:
The variable that is altered during a scientific investigation
Define dependent variable:
the variable that is measured during a scientific investigation
Define random errors:
These are unpredictable variations in results caused by factors such as human errors
Define systematic errors:
These are consistent errors that may arise because of a problem with the experimental design/in a piece of equipment being used
Define anomalous:
Something that is unusual or unexpected and deviates from the normal
One of a series of repeated experimental results that is much larger/smaller than the others is a anomalous result
Define zero error:
A type of systematic error in a measuring instrument
Example the reading on a balance may not reset to zero when there is nothing on the balance
Define filtration:
The separation of a solid from a liquid, using a fine filter paper, which does not allow the solid to pass through
Define crystallization:
The process of forming crystals from a saturated solution
Define simple distillation:
A distillation method for separating the liquid solvent from a solution containing dissolved solids
