All GCSE Chemistry Require practical.

Plan a method to make pure, dry crystals of zinc chloride from zinc carbonate and a dilute acid. [6 marks]

• Use zinc carbonate and dilute hydrochloric acid.

• Add zinc carbonate to the acid in a beaker.

• Stir it.

• Continue adding until the zinc carbonate is in excess.

• If there are excess solid and no reaction, then filter the mixture and left with the solution.

• Heat the solution by using a water bath until reach to crystallization point.

• Leave the solution to crystallise and pat crystals dry with paper towel.

The student tested a samples of dilute sulfuric acid P with sodium hydroxide

Describe how the student could use titrations to find the concentration of sample P. [6 marks]

• Use pipette to measure volume of acid in conical flask.

• Add a few drops of indicator.

• Place conical flask on the white tile.

• Fill the burette with sodium hydroxide solution and add it to the acid drop by drop.

• Swirl until colour changes.

• Read volume from bottom of meniscus and record volume of sodium hydroxide solution added.

• Repeat and take a mean.

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