Problem 69 - Chemistry and Chemical Reactivity

Question

Many foods are fortified with vitamins and minerals. For example, some breakfast cereals have elemental iron added. Iron chips are used instead of iron compounds because the compounds can be converted by the oxygen in air to a form of iron that is not biochemically useful. Iron chips, in contrast, are converted to useful iron compounds in the gut, and the iron can then be absorbed. Outline a method by which you could remove the iron (as iron chips) from a box of cereal and determine the mass of iron in a given mass of cereal. (IMAGE CAN'T COPY)

Step-by-Step Solution

Answer

Use a magnet to extract iron chips from crushed cereal, then weigh the iron to determine its mass.

Step 1: Crush the Cereal

Pour a sample of the cereal into a plastic bag or onto a clean surface. Use a rolling pin or similar object to crush the cereal into small pieces. This increases the surface area and makes it easier to separate the iron chips.

Step 2: Separate Iron using a Magnet

Place a strong magnet inside a plastic bag (to avoid direct contact with food) and move it over the crushed cereal. The iron chips, being magnetic, will stick to the magnet. Carefully remove the magnet away from the cereal with the iron chips attached.

Step 3: Collect and Weigh the Iron

Remove the plastic bag from the magnet, allowing the iron chips to fall onto a piece of weighing paper or into a weighing dish. Use a balance to measure the mass of the collected iron chips.

Step 4: Calculate Percentage of Iron in Cereal

Divide the mass of iron chips by the initial mass of the cereal sample used and multiply by 100 to get the percentage of iron in the cereal. This calculation will give you the approximate concentration of iron by mass in the cereal sample.

Key Concepts

Elemental Iron

Elemental iron is a form of iron that is found naturally in the Earth and can be absorbed by the human body when it’s ingested. It is different from the iron compounds that can be oxidized when exposed to air, losing their nutritional value. Instead, elemental iron is seen as pure particles known as iron filings or chips, which are not prone to this oxidation.

• In food fortification, elemental iron is added because it becomes soluble in the acidic environment of the stomach and turns into usable iron compounds. These compounds are then absorbed by the intestines, providing the necessary iron needed for producing red blood cells.
• Elemental iron fortification is particularly crucial in countries with high incidences of iron-deficiency anemia, as it helps alleviate the condition effectively and inexpensively.

Using elemental iron in foods like cereals helps ensure a stable supply of this key micronutrient, aiding in healthy growth and development.

Magnetic Separation

Magnetic separation is a technique used to separate magnetic materials from non-magnetic materials. In the context of food fortification, it can be used to isolate elemental iron particles from fortified cereals. This simple yet effective method harnesses the magnetic properties of iron

• To perform magnetic separation on a cereal sample, you first need to crush the cereal to increase the iron chips' exposure.
• A magnet is then used to attract these iron particles. By placing a magnet near the crushed cereal, iron chips will gather around it, appearing as tiny specks clinging to the magnet.
• By enclosing the magnet in a plastic bag, direct contact with food items can be avoided, ensuring hygiene.

This process not only demonstrates the presence of iron in cereals but also allows for easy collection and subsequent analysis of the extracted iron.

Mass Determination

Mass determination is a crucial step in analyzing the amount of nutrients or compounds present in a sample. In the instance of analyzing fortification, like determining the amount of iron in cereals, mass determination provides a quantitative measure.

• After collecting the iron using a magnetic separation technique, the next step is to measure its mass.
• A sensitive balance is often used to weigh the iron chips once they have been collected from the magnet.
• The accuracy of this measurement is essential as it directly influences the calculation of the percentage composition of iron in the cereal.

By understanding the mass of iron extracted, one can make informed nutritional evaluations and assess the effectiveness of food fortification.

Micronutrients in Diet

Micronutrients, such as vitamins and minerals like iron, are essential components of a balanced diet. Even though only needed in small amounts, they are vital for nurturing health and aiding physiological functions.

• Iron plays a central role in numerous bodily functions including oxygen transport, energy production, and DNA synthesis.
• Fortification of foods with micronutrients helps combat nutritional deficiencies on a broad scale, as seen with iron in cereals.
• Consuming a diet rich in micronutrients supports overall well-being, enhances immune function, and prevents chronic diseases.

By embedding these nutrients into everyday food items, such as cereals, we take an effective step towards improving nutrition without requiring drastic changes in eating habits.