Solutions

Overview

Welcome, candidates in Ghana, to our detailed course material on the topic of Solutions in Chemistry. This topic delves into the essential aspects of preparing solutions from liquid solutes, determining their concentration through various parameters, and understanding the significance of different types of solution standards.

Preparation of Solutions from Liquid Solutes:

One of the primary objectives of this course material is to guide you through the systematic steps involved in preparing solutions from liquid solutes. This process involves accurately measuring the quantity of the solute and solvent to achieve the desired concentration. Understanding the intricacies of this preparation method is crucial in various chemical experiments and analyses.

Determination of Concentration:

Another fundamental aspect of this course material is the determination of the concentration of liquid solutes. Through parameters such as density, weight/volume (w/v), weight/weight (w/w), specific gravity, relative molecular mass, molar mass, and percentage purity, you will learn how to calculate the concentration of a solution accurately. These calculations are essential in ensuring the effectiveness of the solution in different chemical reactions and applications.

Types of Standards:

In the study of solutions, it is crucial to differentiate between primary standard, secondary standard, and standardized solutions. Each type plays a specific role in analytical chemistry and quality control processes. Primary standards are highly pure compounds used for precise titrimetric analyses, while secondary standards are standardized against primary standards. Standardized solutions are solutions of known concentrations employed in various laboratory procedures.

Practical Applications:

Throughout this course material, you will also gain insights into practical scenarios where the knowledge of solution preparation and standards is applied. By understanding the method of dilution and its significance in adjusting solution concentrations, you will be equipped to handle real-world chemical experiments and laboratory tasks effectively.

Embracing the details within this course material will not only enhance your understanding of solutions in chemistry but also prepare you for intricate chemical analyses and experiments. Let's delve into the world of solutions and unlock the mysteries they hold.

Objectives

  1. Understand the steps involved in the preparation of solutions from liquid solutes
  2. Determine the concentration of liquid solutes using various parameters such as density, w/v, w/w, specific gravity, relative molecular mass, molar mass, and % purity
  3. Differentiate between primary standard, secondary standard, and standardized solutions
  4. Apply knowledge of preparation of solutions through dilution method in practical scenarios

Lesson Note

Solutions are homogeneous mixtures composed of two or more substances. In a solution, a solute is dissolved in another substance known as the solvent. Typically, the solvent is present in a greater amount, and the solute is present in a lesser amount. Solutions can be formed with various combinations of solutes and solvents, including gases, liquids, and solids.

Lesson Evaluation

Congratulations on completing the lesson on Solutions. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. What is the formula for determining the concentration of a solution given its w/v? A. C = (m/v) * 100% B. C = m/v C. C = v/m D. C = m * v% Answer: A. C = (m/v) * 100%
  2. Which of the following parameters can be used to determine the concentration of a liquid solute? A. Specific gravity B. Molar mass C. % Purity D. Relative molecular mass Answer: C. % Purity
  3. In the preparation of solutions from liquid solutes, what is a primary standard solution primarily used for? A. Unknown concentration determination B. Reacting with secondary standard solutions C. Calibration of laboratory equipment D. Standardizing solutions Answer: D. Standardizing solutions
  4. In the context of solutions, what do the terms w/w and w/v represent? A. Weight/Volume and Weight/Weight respectively B. Water/Volume and Water/Weight respectively C. Mass/Volume and Mass/Weight respectively D. Mixture/Volume and Mixture/Weight respectively Answer: A. Weight/Volume and Weight/Weight respectively
  5. Which of the following elements is a member of the first transition series? A. Sodium B. Potassium C. Iron D. Calcium Answer: C. Iron

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Past Questions

Wondering what past questions for this topic looks like? Here are a number of questions about Solutions from previous years

Question 1 Report

Addition of sodium chloride to water to form a solution would  lead to?


Question 1 Report

A solution is prepared by dissolving I .96g of H2SO4 in 250 cm3 of its solution. What is the concentration in moles per dm3?


Question 1 Report

TEST OF PRACTICAL KNOWLEDGE QUESTION


(a) If you were provided with anhydrous Na\(_2\)CO\(_3\), spatula and stirrer;

(i) list three other materials you would require to prepare a standard solution of Na\(_2\)CO\(_3\)

(ii) state what you would observe on adding diluted H\(_2\)SO\(_4\) to a portion of the Na\(_2\)CO\(_3\)

 

(b)(i) Describe briefly one chemical test you would perform to distinguish between zinc ions and aluminium ions in solution.

(ii) Mention one laboratory reagent you would use to;

I. produce ammonia from (NH\(_4\))\(_2\)SO\(_4\)

II. differentiate between precipitates of AgCl and Agl

lll. dehydrate ethanol

 

(c) Give the reason for each of the following laboratory practices

(i) Aqueous solutions of FeSO\(_4\) are freshly prepared when required for use.

(ii) The first jar of hydrogen collected during its preparation is discarded 


Practice a number of Solutions past questions