A student poured 50 cm³ water into a beaker and measured the water’s temperature - Edexcel - GCSE Chemistry - Question 4 - 2019 - Paper 1
Question 4
A student poured 50 cm³ water into a beaker and measured the water’s temperature.
The student added 1.00 g calcium chloride to the water, stirred the mixture and th... show full transcript
Worked Solution & Example Answer:A student poured 50 cm³ water into a beaker and measured the water’s temperature - Edexcel - GCSE Chemistry - Question 4 - 2019 - Paper 1
Step 1
Give the name of the apparatus that could be used to measure 1.00 g of calcium chloride.
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Answer
The apparatus that could be used to measure 1.00 g of calcium chloride is a weighing scale, specifically a top pan balance.
Step 2
Explain, using these results, the type of heat energy change that occurs when calcium chloride dissolves in water.
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Answer
The temperature of the mixture increased from 21 °C to 32 °C after adding calcium chloride, indicating that the dissolution of calcium chloride in water is an exothermic process. This means that heat is released into the solution as the salt dissolves, causing the temperature to rise.
Step 3
Which hazard symbol would be expected to be seen on a container of calcium chloride?
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The hazard symbol expected on a container of calcium chloride is the one indicating irritation or health hazard, typically represented with a triangle and exclamation mark.
Step 4
Give a safety precaution that the student should take during the experiment.
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The student should wear gloves and safety goggles during the experiment to protect against potential skin and eye irritation from calcium chloride.
Step 5
State one way in which the apparatus could be changed to reduce the amount of heat energy lost during the experiment.
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One way to reduce heat energy loss is to use an insulated container or beaker to minimize heat exchange with the surrounding environment.
Step 6
Calculate the volume of this solution, in cm³, that contains 9.0 g of calcium chloride.
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Answer
To calculate the volume of the calcium chloride solution needed to contain 9.0 g of calcium chloride, we can use the formula:
