Problem 22 - Chemistry The Science in Context

Question

Hemoglobin in Blood A typical adult body contains \(6.0 \mathrm{L}\) of blood. The hemoglobin content of blood is about \(15.5 \mathrm{g} / 100.0 \mathrm{mL}\) of blood. The approximate molar mass of hemoglobin is \(64,500 \mathrm{g} / \mathrm{mol} .\) How many moles of hemoglobin are present in a typical adult?

Step-by-Step Solution

Answer

Answer: Approximately 0.0144 moles of hemoglobin are present in a typical adult.

Step 1: Convert the volume of blood from liters to milliliters

First, we need to convert the volume of blood in a typical adult body from liters to milliliters. Since 1 liter is equal to 1000 milliliters (1 L = 1000 mL), we will multiply the given volume by 1000: (6.0 L) * (1000 mL / 1 L) = 6000 mL

Step 2: Calculate the mass of hemoglobin in the entire volume of blood

Next, we will calculate the mass of hemoglobin in 6000 mL of blood using the given hemoglobin content (15.5 g / 100.0 mL): (6000 mL) * (15.5 g / 100.0 mL) = 930 g

Step 3: Convert the mass of hemoglobin to moles

Finally, we will convert the mass of hemoglobin (930 g) to moles of hemoglobin using the given molar mass (64,500 g/mol). To do this, we will divide the mass by the molar mass: (930 g) / (64,500 g/mol) = 0.0144 mol The number of moles of hemoglobin present in a typical adult is approximately 0.0144 moles.

Key Concepts

Hemoglobin

Hemoglobin is a vital protein found in red blood cells, responsible for transporting oxygen throughout the body. Each hemoglobin molecule can bind up to four oxygen molecules, which it picks up in the lungs and carries to tissues that require oxygen. Without hemoglobin, our body would struggle to efficiently deliver oxygen to where it's needed most.

This protein is not only crucial for oxygen supply but also plays a role in carrying carbon dioxide back to the lungs for exhalation. Understanding hemoglobin's role in the circulatory system is essential for comprehending its quantitative analysis, such as calculating moles in a given volume of blood. This helps in determining whether the hemoglobin levels in your bloodstream are adequate for optimal health.

Molar Mass

Molar mass is a fundamental concept in chemistry. It refers to the mass of one mole of a substance, usually measured in grams per mole (g/mol). For hemoglobin, the molar mass is approximately 64,500 g/mol.

To comprehend molar mass, recognize that it links the mass of a substance to the number of particles in that mass. Calculating molar mass allows you to convert between grams and moles effortlessly, which is essential for quantitative chemical analysis. In the context of hemoglobin, knowing its molar mass allows us to determine how much of it—measured in moles—is in a certain mass of blood. This is crucial for applications in medical fields, where precise measurements can influence diagnosis and treatment.

Unit Conversion

Unit conversion is a core skill in scientific calculations. It involves converting one unit of measurement to another to ensure accuracy and consistency in experiments and calculations.

In chemistry, converting between units like liters and milliliters or grams and moles is common. For example, when dealing with blood volume, converting from liters to milliliters is often necessary because laboratory measurements are frequently made in milliliters. Understanding that 1 liter equals 1000 milliliters simplifies calculations, enabling you to work conveniently with differing units.

• For example, 6.0 L of blood converts to 6000 mL by multiplying by 1000.

Mastering unit conversion is essential for tackling problems that require various measurements in scientific research.

Chemical Quantities

Chemical quantities refer to measurable amounts of substances in a chemical process. These quantities allow scientists to compute how much of a chemical element or compound is involved in a reaction or present in a mixture.

In our example, chemical quantities are used to determine the number of moles of hemoglobin in a typical body. Using equations and conversion factors, such as the given 15.5 g/100 mL concentration of hemoglobin, enables precise calculations.

• Finding the mass of hemoglobin is achieved by multiplying the volume of blood with the hemoglobin concentration.
• Moles are calculated by dividing the mass by the compound's molar mass.

These processes underscore the importance of chemical quantities in both theoretical and applied chemistry.