Video 2 Preparation of solid solution

Summary

This lesson teaches how to prepare solid solutions, focusing on molar and mass concentrations. It introduces basic concepts like solutions, solutes, and solvents, and demonstrates how to prepare a copper sulfate solution with a concentration of 0.05 mol/L. The process includes precise calculations for determining the mass of solute, using appropriate glassware such as volumetric flasks, and following careful steps to ensure accurate results. The video also includes exercises to reinforce these concepts, encouraging viewers to apply their knowledge in practical lab situations.

Takeaways

• 😀 Solutions are homogeneous mixtures made up of a solvent and solute, with water being a common solvent in aqueous solutions.
• 😀 The molar concentration (C) is the number of moles of solute divided by the volume of solution in liters, measured in moles per liter.
• 😀 Mass concentration (Cm) is the mass of solute in grams divided by the volume of the solution in liters, measured in grams per liter.
• 😀 A chemist must use specific glassware and follow exact procedures to prepare solutions with precise concentrations.
• 😀 Preparing a solution of copper sulfate requires materials like a digital balance, spatula, water glass, and volumetric flask.
• 😀 The mass of copper sulfate needed for a 0.05 M solution is calculated using the molar mass and the desired volume of solution.
• 😀 The molar mass of copper sulfate is calculated based on the atomic masses of copper, sulfur, and oxygen, resulting in 160 grams per mole.
• 😀 The difference between a volumetric flask and a graduated flask lies in their accuracy; a volumetric flask is more accurate for precise volumes.
• 😀 The procedure to prepare a copper sulfate solution includes weighing the solute, dissolving it in water, and filling the volumetric flask to the mark.
• 😀 When filling a volumetric flask, the line should be viewed at eye level to ensure accuracy when adding distilled water.
• 😀 In exercises, the correct glassware and calculations must be used to determine molar concentration and the necessary mass of solute for a given solution.

Q & A

What is a solution?

A solution is a homogeneous mixture made up of a solvent and at least one solute. The solvent dissolves the solute, and if the solvent is water, the solution is called an aqueous solution.

What is the difference between an aqueous and a non-aqueous solution?

An aqueous solution uses water as the solvent, such as salty water where salt is the solute. A non-aqueous solution uses a solvent other than water, such as acetone dissolving varnish.

What is molar concentration?

Molar concentration (denoted as 'C') is the number of moles of solute per liter of solution, typically expressed in moles per liter (mol/L).

What is mass concentration?

Mass concentration (denoted as 'Cm') is the mass of solute in grams per liter of solution, typically expressed in grams per liter (g/L).

What materials are needed to prepare a copper sulfate solution of 0.05 mol/L concentration?

The materials required are a digital balance, spatula, water glass, funnel, wash bottle with distilled water, copper sulfate crystals (solute), and a 500 mL volumetric flask.

How do you calculate the mass of copper sulfate needed for a solution?

The mass of copper sulfate is calculated by multiplying the molar concentration, the molar mass of copper sulfate, and the volume of the solution. The molar mass of copper sulfate is 160 g/mol, and for a 0.05 mol/L solution, the required mass is 4 grams.

What is the difference between a volumetric flask and a graduated flask?

A volumetric flask is designed for measuring a specific volume accurately, typically with a single graduation mark. A graduated flask, such as a beaker or graduated cylinder, has multiple graduation marks and is less precise.

Why is it important to use a volumetric flask for preparing solutions?

Volumetric flasks are used for accurate volume measurements, ensuring precise concentrations in the solution. This is especially important for scientific experiments and medical solutions.

What is the procedure for preparing a copper sulfate solution?

The procedure includes weighing the copper sulfate, dissolving it in a volumetric flask with distilled water, and shaking it to ensure homogeneity. The final volume is adjusted up to the mark on the flask with distilled water.

What should you pay attention to when filling a volumetric flask to the line mark?

When filling the volumetric flask to the line, ensure that your eyes are at the same horizontal level as the line mark to avoid parallax error and ensure accuracy.