C4.7 Titrations Flashcards
Why is acid heated in chemical reaction
To speed up the reaction
After the reaction is complete some solid copper oxide remains why?
Acid all used up
What student should do to solution to form copper oxide
Allow heating, cooling, evaporate
Why mass of copper sulfate crystals was less than expected
Some copper sulfate may have been lost during the experiment
Why is solution filtered
To remove copper oxide
How could you make crystals form faster from the copper sulphate solution
Heat the solution
How could you test the white copper sulphate as a test for water
Add water
Colour changes blue
Balanced symbol equation for reaction of hydrochloric acid with copper (II) carbonate
CuCO3 + 2HCl —————–> CuCl2 + CO2 + H2O
How to prepare a sample of pure dry hydrated copper (II) chloride crystals from excess solid copper (I) carbonate and 25cm3 of dilute hydrochloric acid
Measure 25cm3 of hydrochloric acid
Place hydrochloric acid in container
Add copper(II) carbonate until excess
Filter
Evaporate until half volume
Allow to cool and crystallise
Filter off the crystals
Dry between 2 sheets of paper in low temperature
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Pipette
Burette
The long one with the twist on and off
What should be used to add dilute sulfuric acid
Burette
How solid ammonium sulfate should be obtained from this solution
Use of bunsen burner until all water evaporates
Why universal indicator must not be used in titration experiments
No shape change in colour gradual
What could be added to a practical to ensure accurate results obtained
Use of white tile
Wash inside of conical flask with a little distilled water
