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Ch.3 - Molecules, Compounds & Chemical Equations
Tro - Chemistry: A Molecular Approach 4th Edition
Tro4th EditionChemistry: A Molecular ApproachISBN: 9780134112831Not the one you use?Change textbook
All textbooksTro 4th EditionCh.3 - Molecules, Compounds & Chemical EquationsProblem 77
Chapter 3, Problem 77

The iodide ion is a dietary mineral essential to good nutrition. In countries where potassium iodide is added to salt, iodine deficiency (or goiter) has been almost completely eliminated. The recommended daily allowance (RDA) for iodine is 150 mg/day. How much potassium iodide (76.45% I) should you consume if you want to meet the RDA?

Verified step by step guidance
1
Identify the percentage of iodine in potassium iodide, which is given as 76.45%.
Determine the amount of iodine needed per day, which is 150 mg according to the RDA.
Set up a proportion to find the amount of potassium iodide needed to provide 150 mg of iodine. Use the formula: \( \text{Amount of KI} = \frac{\text{RDA of Iodine}}{\text{Percentage of Iodine in KI}} \).
Substitute the known values into the formula: \( \text{Amount of KI} = \frac{150 \text{ mg}}{0.7645} \).
Solve the equation to find the amount of potassium iodide needed to meet the RDA for iodine.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Iodine and Its Importance

Iodine is an essential trace element necessary for the synthesis of thyroid hormones, which regulate metabolism, growth, and development. A deficiency in iodine can lead to health issues such as goiter and hypothyroidism. The recommended daily allowance (RDA) for iodine is 150 micrograms for adults, highlighting its critical role in human health.

Potassium Iodide Composition

Potassium iodide (KI) is a compound that provides iodine in a bioavailable form. It consists of potassium and iodide ions, with iodide being the active form that the body utilizes. The percentage of iodine in potassium iodide (76.45%) indicates that for every 100 grams of KI, 76.45 grams is iodine, which is crucial for calculating the amount needed to meet the RDA.
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Calculating Dosage from Composition

To determine how much potassium iodide is needed to meet the iodine RDA, one must use the composition percentage of iodine in KI. By setting up a proportion based on the RDA and the percentage of iodine in KI, one can calculate the required mass of potassium iodide. This involves basic algebraic manipulation to ensure the correct dosage is consumed to meet nutritional needs.
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