Mixing Solutions: Practical Applications and Concentration Calculation

Objectives

1. Understand the basic concepts of solutions and mixtures without chemical reaction.

2. Calculate initial and final concentrations of mixed solutions.

3. Develop problem-solving skills applied to real-world scenarios.

4. Apply theoretical knowledge in practical and experimental activities.

Contextualization

Solutions are present in our daily lives in various forms, from the coffee we make in the morning to the liquid medications we consume when we are sick. Understanding how these solutions are formed and how we can calculate their concentrations is essential not only for chemistry but also for various fields of knowledge and the job market. For example, in the pharmaceutical industry, knowledge about solutions is crucial for formulating medications with the correct dosage. In the food industry, these concepts are used to ensure the quality and flavor of products. Thus, learning about mixtures of solutions without chemical reaction has significant and direct practical applications in various professional fields.

Relevance of the Theme

Understanding the concentrations of solutions is fundamental in many industrial sectors, such as pharmaceuticals and food. This knowledge ensures accuracy in product formulations, guaranteeing their effectiveness and safety. Furthermore, developing calculation and problem-solving skills in real contexts prepares students for market challenges, making them more capable of dealing with practical situations and applying theories efficiently.

Definition of Solutions and Mixtures

Solutions are homogeneous mixtures of two or more substances. A solution consists of a solute, which is the dissolved substance, and a solvent, which is the substance that dissolves the solute. Mixtures can be homogeneous, like solutions, or heterogeneous, where the components are visibly separate.

• Solutions are homogeneous mixtures.

• Solute is the dissolved substance.

• Solvent is the substance that dissolves the solute.

• Mixtures can be homogeneous or heterogeneous.

Types of Solutions: Saturated, Unsaturated, and Supersaturated

Solutions can be classified according to the amount of solute dissolved in relation to the maximum amount that the solvent can dissolve. Saturated solutions contain the maximum amount of solute that can be dissolved. Unsaturated solutions have less solute than the maximum, and supersaturated solutions have more solute than the maximum, being unstable.

• Saturated solutions have the maximum amount of dissolved solute.

• Unsaturated solutions have less solute than the maximum.

• Supersaturated solutions have more solute than the maximum and are unstable.

Calculation of Concentrations: Molarity, Molality, and Mass Percentage

The concentration of a solution can be expressed in various ways. Molarity (M) is the number of moles of solute per liter of solution. Molality (m) is the number of moles of solute per kilogram of solvent. Mass percentage is the mass of the solute divided by the total mass of the solution, multiplied by 100.

• Molarity (M) is moles of solute per liter of solution.

• Molality (m) is moles of solute per kilogram of solvent.

• Mass percentage is the mass of the solute divided by the total mass of the solution, multiplied by 100.

Practical Applications

• In the pharmaceutical industry, accuracy in mixing solutions is crucial for formulating medications with the correct dosages.
• In the food industry, the calculation of concentrations is used to ensure the quality and flavor of products.
• In research laboratories, the preparation of solutions with specific concentrations is essential for carrying out precise experiments.

Key Terms

• Solutions: Homogeneous mixtures of two or more substances.

• Mixtures: Combinations of two or more substances that can be homogeneous or heterogeneous.

• Molarity: Number of moles of solute per liter of solution.

• Molality: Number of moles of solute per kilogram of solvent.

• Mass Percentage: Mass of the solute divided by the total mass of the solution, multiplied by 100.

Questions

• How can the knowledge of solution concentrations be applied in areas other than the pharmaceutical and food industries?

• What were the biggest challenges encountered during the practical activity of creating an isotonic drink and how did you overcome them?

• How can accuracy in concentration calculations impact the safety and effectiveness of products in the market?

Conclusion

To Reflect

Throughout this lesson, we explored the importance of solutions and mixtures without chemical reaction, especially in the industrial context. Understanding how to calculate concentrations of solutions is an essential skill, not just for chemistry but for various fields of knowledge and the job market. The practical activity of creating an isotonic drink highlighted how theoretical knowledge is applied in practice, reinforcing the need for precision and care in calculations. Reflecting on these applications helps us see the relevance of the concepts studied and the importance of developing practical skills that are highly valued in the job market.

Mini Challenge - Practical Challenge: Mixing Solutions with Precision

Consolidate the understanding of the concepts of solutions and mixtures without chemical reaction through a practical challenge that involves calculating concentrations and creating a specific solution.

• Divide into groups of 4-5 students.
• Receive the solutions provided by the teacher, which include different concentrations of NaCl and glucose.
• Calculate the final concentration of a specific mixture using the dilution formula: C1V1 = C2V2.
• Mix the solutions accurately to create an isotonic drink with approximately 0.9% NaCl and 5% glucose.
• Document the calculations and the mixing process.
• Present the results to the rest of the class, explaining the challenges encountered and how they were overcome.