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Measuring rate of reaction
There is no one best way to measure rate of reaction, it depends on the
substances used etc.
Substance Type Procedure
One substance is an acid or base Measure pH (indicator, titration
One product is a gas Measure gas volume (Upside down
measuring cylinder etc.)
An obvious viewable change occurs Track colour change(colorimeter
etc.) or track precipitate forming
Colorimeters measure the transparency of a substance by shining light
through it. You can take a reading at a point in the reaction and track
the percentage of light transmitted.