5 (a) A few drops of phenolphthalein indicator are added to dilute ethanoic acid - Edexcel - GCSE Chemistry - Question 5 - 2016 - Paper 1
Question 5
5 (a) A few drops of phenolphthalein indicator are added to dilute ethanoic acid.
Choose the colour of this mixture.
Put a cross (✗) in the box next to your answer.
... show full transcript
Worked Solution & Example Answer:5 (a) A few drops of phenolphthalein indicator are added to dilute ethanoic acid - Edexcel - GCSE Chemistry - Question 5 - 2016 - Paper 1
Step 1
5 (a) Choose the colour of this mixture.
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Answer
The colour of the mixture with phenolphthalein indicator added to dilute ethanoic acid is A, colourless. This indicates that the solution is acidic, and phenolphthalein remains colourless in acidic conditions.
Step 2
5 (b)(i) Give the name of the type of reaction that occurs when ethanoic acid reacts with sodium hydroxide.
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Answer
The type of reaction that occurs is called 'neutralisation', as it involves an acid reacting with a base to form a salt and water.
Step 3
5 (b)(ii) Write the word equation for this reaction.
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Answer
The word equation for the reaction is:
ethanoic acid + sodium hydroxide → sodium ethanoate + water
Step 4
5 (c)(i) State why vinegar is sprinkled on some foods.
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Answer
Vinegar is sprinkled on some foods because it acts as a flavouring agent, enhancing the taste of the food.
Step 5
5 (c)(ii) State why other foods are stored in vinegar.
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Answer
Other foods are stored in vinegar as it acts as a preservative. The acetic acid in vinegar helps prevent bacterial growth and spoilage.
Step 6
5 (d) Describe how you would prepare a pure solution of magnesium ethanoate and how you would obtain pure, dry magnesium ethanoate crystals from that solution.
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Answer
To prepare a pure solution of magnesium ethanoate, follow these steps:
Mixing: Place dilute ethanoic acid in a beaker and gradually add magnesium carbonate while stirring to ensure complete reaction. Small amounts should be added until no more fizzing occurs.
Filtration: Filter the mixture using filter paper to remove any unreacted magnesium carbonate.
Making Crystals: Evaporate the filtrate in an evaporating basin until crystals of magnesium ethanoate start to form. Allow the solution to cool to enhance crystal formation.
Final Steps: Wash the obtained crystals with cold water and dry them using absorbent paper to obtain pure, dry magnesium ethanoate.
