6 (a) A technician made some dilute sodium hydroxide solution by carefully adding some solid sodium hydroxide to pure water - Edexcel - GCSE Chemistry - Question 6 - 2013 - Paper 1
Question 6
6 (a) A technician made some dilute sodium hydroxide solution by carefully adding some solid sodium hydroxide to pure water.
This is the hazard symbol on a bottle o... show full transcript
Worked Solution & Example Answer:6 (a) A technician made some dilute sodium hydroxide solution by carefully adding some solid sodium hydroxide to pure water - Edexcel - GCSE Chemistry - Question 6 - 2013 - Paper 1
Step 1
State what this symbol shows about sodium hydroxide.
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Answer
The symbol indicates that sodium hydroxide is corrosive, meaning it can damage skin or clothes and can cause burns.
Step 2
Sodium hydroxide solution reacts with dilute hydrochloric acid.
What type of reaction is this?
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Answer
The reaction between sodium hydroxide and dilute hydrochloric acid is a neutralisation reaction.
Step 3
Explain the meaning of catalyst.
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A catalyst is a substance that increases the rate of a reaction without being consumed in the process. It works by lowering the activation energy required for the reaction to occur.
Step 4
Describe what this shows about the effect of the surface area of calcium carbonate on the rate of this reaction.
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Answer
The results indicate that smaller pieces of calcium carbonate have a larger surface area, leading to a higher reaction rate. Smaller pieces produce more carbon dioxide in a shorter time than larger pieces.
Step 5
Describe how you could use magnesium ribbon and a solution of hydrochloric acid to show that decreasing the concentration of the hydrochloric acid changes the rate of this reaction.
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To demonstrate this, one could prepare solutions of hydrochloric acid at different concentrations, ensuring that all other factors such as temperature and volume remain constant. By adding equal lengths of magnesium ribbon into each solution and measuring the time taken for the magnesium to react and produce hydrogen gas, it would be observable that the reaction is faster with higher concentrations of hydrochloric acid and slower with lower concentrations.
