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iodine is required for a healthy diet - Scottish Highers Chemistry - Question 11 - 2023
Question 11
iodine is required for a healthy diet. Food grown in certain parts of the world is low in iodine. To prevent iodine deficiency in people's diets, table salt can be '... show full transcript
Worked Solution & Example Answer:iodine is required for a healthy diet - Scottish Highers Chemistry - Question 11 - 2023
Step 1
Describe a procedure to accurately weigh out a 50.0 g sample of iodised table salt.
Answer
To accurately weigh out a 50.0 g sample of iodised table salt, follow these steps:
- Use a Balance: Place a clean dry weighing boat on a balance and tare it to zero.
- Add Salt: Carefully add iodised salt to the weighing boat until the display shows 50.0 g.
- Transfer: Once the desired mass is achieved, transfer the salt to a suitable container for dissolving in water.
Step 2
Step 3
Calculate the average volume, in cm³, of sodium thiosulfate solution that should be used to determine the number of moles of iodine released.
Answer
To calculate the average volume of sodium thiosulfate solution used, sum the volumes of the three samples and divide by three: ext{Average Volume} = rac{10.0 + 9.4 + 9.6}{3} = rac{29.0}{3} = 9.67 ext{ cm}^3
Step 4
Calculate the number of moles of iodine released from 50 cm³ of the standard salt solution.
Answer
First, use the average volume of sodium thiosulfate ( ext{9.67 cm}^3) in the formula: [ ext{Number of moles of iodine} = ext{Volume} imes ext{Concentration} imes ext{Mole Ratio} ] Since the concentration of sodium thiosulfate is 0.0010 mol L⁻¹: