The following apparatus is used in an experiment to change when aqueous sodium hydroxide is added to dilute nitric acid.
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A student used the following method:
Using a measuring cylinder, add 25 cm. aqueous sodium hydroxide to the
polystyrene cup and record the temperature.
• Using a different measuring cylinder, add 5 cmº dilute nitric acid to the cup and
stir the mixture
Record the temperature of the mixture.
• Add a further 5 cm dilute nitric acid, stir the mixture and record the
temperature
• Continue adding 5 cm portions of dilute nitric acid until a total of 35 cm has
been added
Why is it better to mix the solutions in a polystyrene cup rather than in a glass
beaker?
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