A person needs on average of \(2.0 \mathrm{mg}\) of riboflavin (vitamin \(\mathrm{B}_{2}\) ) per day. How many grams of butter should be taken by the person per day if it is the only source of riboflavin? Butter contains \(5.5 \mu \mathrm{g}\) riboflavin per \(\mathrm{g}\). (a) \(363.6 \mathrm{~g}\) (b) \(2.75 \mathrm{mg}\) (c) \(11 \mathrm{~g}\) (d) \(19.8 \mathrm{~g}\)

Stoichiometry refers to the calculation of relative quantities of reactants and products in chemical reactions. It's a foundational concept in chemistry that applies the laws of conservation of mass and constant proportions. Essentially, stoichiometry allows us to predict the amounts of substances consumed and produced in a given chemical process.

In the context of nutritional science, we use similar principles when determining how much of a nutrient - like riboflavin - is required to meet dietary needs. Here we’re not dealing with a chemical reaction per se, but the underlying concept of proportionality is very much akin to that found in stoichiometry. Instead of balancing a chemical equation, we balance the dietary

Unit conversion is a critical skill in both chemistry and everyday scenarios like nutrition. It involves changing one unit of measure to another without altering the actual amount. In chemistry, this could involve converting moles to grams, while in our exercise, we converted the daily riboflavin requirement from milligrams to micrograms.

This is essential, as mismatched units can lead to incorrect conclusions. The process often entails multiplication or division by a conversion factor, which is a ratio that represents equivalence between units. For instance, the conversion factor from milligrams to micrograms is 1 mg = 1000 µg. Therefore, we convert 2.0 mg of riboflavin to 2000 µg to proceed with the proportion calculation based on the given information about butter's riboflavin content.

Solving proportions is about finding the unknown part of a relationship between two ratios that express the same relationship. When we set up a proportion in an equation, we state that two ratios are equivalent. In our scenario, the proportion helped to find the unknown amount of butter based on its riboflavin content per gram.

The cross-multiplication method is a common technique to solve such proportions. After setting up the proportion of riboflavin to butter and riboflavin required for the day, cross-multiplication allows us to isolate the variable — in this case, the amount of butter needed — and solve it. This is particularly valuable in various fields such as cooking, manufacturing, and even medication dosing, where proportions ensure the correct amounts are used or consumed.

Vitamin B2, also known as riboflavin, is an essential nutrient that must be obtained from the diet. It plays crucial roles in energy production and the metabolism of fats, drugs, and steroids. Since the human body doesn't produce it, we must consume it through sources like dairy, eggs, green leafy vegetables, lean meats, legumes, and nuts.

Understanding how much of these foods to consume requires knowledge of their riboflavin content, as seen with the butter in our exercise. When butter, or any other riboflavin source, is the sole provider of this vitamin, it's critical to calculate the necessary quantity to meet the body's needs. In today's age of dietary restrictions and preference for individualized nutrition plans, knowing how to calculate these quantities assures adequate intake and avoids the detriments of nutrient deficiencies.