Investigating pH
This practical lesson covers:
- Neutralisation reactions between powdered calcium hydroxide or calcium oxide and hydrochloric acid
Investigating pH
Aim
To investigate the change in pH on adding powdered calcium hydroxide or calcium oxide to a fixed volume of dilute hydrochloric acid.
Background information
Neutralisation reactions take place when an acid reacts with a base. Acids have a pH less than 7 and bases have a pH greater than 7. In this practical, you will react powdered calcium hydroxide or calcium oxide with dilute hydrochloric acid. The change in pH is measured by observing the colour change of universal indicator.
What is the purpose of adding universal indicator in the experiment?
to compare the color to a pH chart
to measure the volume of hydrochloric acid
to dissolve the calcium hydroxide
to neutralise the hydrochloric acid
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Which substance is added one spatula at a time during the experiment?
calcium hydroxide or calcium oxide
hydrochloric acid
dilute hydrochloric acid
universal indicator
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When should the addition of calcium hydroxide or calcium oxide be stopped?
when the pH becomes acidic
when the pH becomes neutral
when the pH remains constant
when the pH becomes alkaline
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