Prepare 250 cm3 of 0.1 M HCl solution

 

Abstract

This experiment aims to prepare a 0.1 M (molar) hydrochloric acid (HCl) solution with a volume of 250 cm³. Dilution calculations are used to achieve the desired concentration from a stock solution of higher concentration.

Introduction

Hydrochloric acid (HCl) is a common laboratory reagent used in various chemical reactions and analyses. The preparation of a specific molarity solution involves dilution of a stock solution to achieve the desired concentration. This experiment provides practical experience in dilution techniques and the calculation of molarity.

Details of the Experiment

Materials Required

• Hydrochloric acid (HCl) stock solution
• Distilled water
• Graduated cylinder or volumetric flask
• Stirring rod
• Beaker

Procedure

1. Measure 25 cm³ of the HCl stock solution using a graduated cylinder or volumetric flask.
2. Add the measured HCl solution to a 250 cm³ volumetric flask.
3. Fill the volumetric flask with distilled water up to the mark (250 cm³), using a dropping pipette or burette for precise addition.
4. Cap and mix the contents of the flask thoroughly to ensure uniform distribution.

Observations and Calculations

No observations are made during the preparation process. The calculation involves determining the volume of stock solution needed to achieve the desired concentration.

Conclusion

A 0.1 M HCl solution with a volume of 250 cm³ is successfully prepared through dilution of the stock solution.

Precautions

• Handle hydrochloric acid with care, as it is corrosive.
• Use proper protective equipment, including gloves and goggles.
• Ensure accurate measurement of volumes to achieve the desired concentration.
• Cap the volumetric flask securely to prevent spills or contamination.

Short Questions with Answers

1. What does "M" stand for in "0.1 M HCl solution"?
   Answer: Molarity
2. What is the molarity of the prepared HCl solution?
   Answer: 0.1 M
3. What is the purpose of diluting the HCl stock solution?
   Answer: To achieve the desired concentration.
4. Why is distilled water used instead of tap water in the preparation?
   Answer: Distilled water is free from impurities.
5. What is the role of a volumetric flask in this experiment?
   Answer: To accurately measure and dilute the stock solution.
6. What safety precautions should be followed when handling hydrochloric acid?
   Answer: Wear gloves and goggles, work in a well-ventilated area.
7. What is the significance of mixing the solution thoroughly?
   Answer: To ensure uniform distribution of the components.
8. How is the final volume of the solution adjusted?
   Answer: By adding distilled water up to the mark on the volumetric flask.
9. Why is it important to cap the volumetric flask securely?
   Answer: To prevent evaporation and contamination.
10. What is the primary objective of preparing a specific molarity solution?
    Answer: To accurately control the concentration of the solution for various applications.
11. What equipment is used to measure precise volumes in the experiment?
    Answer: Graduated cylinder or volumetric flask.
12. What should be done if the prepared solution exceeds the desired volume?
    Answer: Add more distilled water to dilute.
13. What is the role of hydrochloric acid in laboratory experiments?
    Answer: It is commonly used as a reagent and for pH adjustment.
14. Why is it necessary to mix the solution thoroughly?
    Answer: To ensure that the concentration is uniform throughout the solution.
15. How can the concentration of the HCl solution be adjusted?
    Answer: By diluting with water.
16. What precaution should be taken when handling concentrated acids?
    Answer: Handle with care and avoid contact with skin and eyes.
17. What is the purpose of using distilled water instead of tap water?
    Answer: Distilled water is free from impurities that could affect the concentration of the solution.
18. Why is it important to accurately measure the volume of the HCl stock solution?
    Answer: To ensure the correct dilution and concentration of the final solution.
19. What is the function of the stirring rod in the experiment?
    Answer: To mix the components thoroughly for uniform distribution.
20. What precaution should be taken when adding the HCl stock solution to the volumetric flask?
    Answer: Pour slowly and carefully to avoid spills.

Multiple Choice Questions (MCQs) with Answers

1. What is the desired molarity of the HCl solution?
   • a) 0.01 M
   • b) 0.1 M
   • c) 1 M
   • d) 10 M
   • Answer: b) 0.1 M
2. What equipment is used to measure precise volumes in the experiment?
   • a) Graduated cylinder
   • b) Beaker
   • c) Test tube
   • d) Flask
   • Answer: a) Graduated cylinder
3. Why is it important to cap the volumetric flask securely?
   • a) To prevent evaporation of the solution
   • b) To avoid contamination
   • c) To ensure accurate measurement
   • d) All of the above
   • Answer: d) All of the above
4. What should be done if the prepared solution exceeds the desired volume?
   • a) Discard the excess solution
   • b) Add more water to dilute
   • c) Heat the solution to evaporate excess
   • d) None of the above
   • Answer: b) Add more water to dilute
5. Which of the following is a suitable alternative to hydrochloric acid for preparing the solution?
   • a) Sodium hydroxide
   • b) Sulfuric acid
   • c) Acetic acid
   • d) Nitric acid
   • Answer: b) Sulfuric acid