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Sodium chloride (table salt) is a white crystalline solid - Junior Cycle Science - Question 11 - 2019
Question 11
Sodium chloride (table salt) is a white crystalline solid. Water is a solvent with a boiling point of 100 °C. Sodium chloride can dissolve in water. A student was a... show full transcript
Worked Solution & Example Answer:Sodium chloride (table salt) is a white crystalline solid - Junior Cycle Science - Question 11 - 2019
Step 1
Step 2
Step 3
Calculate the average boiling point when 4 g of salt was dissolved in 60 cm³ of water.
Answer
To find the average boiling point for 4 g of salt, we should observe the boiling points recorded in the table. The boiling points for 4 g of salt are 103 °C, 105 °C, 104 °C, 106 °C, and 107 °C. To calculate the average:
ext{Average} = rac{103 + 105 + 104 + 106 + 107}{5} = rac{525}{5} = 105 °C.
Step 4
Suggest a reason why the student repeated the investigation five times for each mass of salt used.
Answer
The student repeated the investigation to ensure reliability and accuracy of the data collected. Repeating the experiment helps to minimize errors and provides a more reliable average boiling point for each mass of salt.
Step 5
Does the data support the hypothesis you wrote in part (a)? Explain your answer.
Answer
Yes, the data supports the hypothesis. As the mass of salt increases, the average boiling point also rises. This trend indicates that the addition of sodium chloride elevates the boiling point of the water, consistent with the hypothesis that dissolved salt will alter physical properties of the solution.