In a physical science class, four students are experimenting with distinct techniques for dissolving laundry soap in water. Each student mixes 20 grams of soap with 1000 mL of water. The table illustrates the varied methods employed by each student.

Question

Student: Darien | Form of soap: Solid cube | Water temperature: 50°C | Method of combination: No stirring
Student: Heather | Form of soap: Powder | Water temperature: 105°C | Method of combination: Vigorous stirring
Student: Abdullah | Form of soap: Solid cube | Water temperature: 50°C | Method of combination: Gentle stirring
Student: Larissa | Form of soap: Powder | Water temperature: 75°C | Method of combination: Gentle stirring

Answer 1

This experiment presents an opportunity to investigate how different variables—such as form of soap, water temperature, and method of stirring—can affect the dissolution of laundry soap in water.

Here's an analysis of each student's method:

1. Darien

   • Form of soap: Solid cube
   • Water temperature: 50°C
   • Method of combination: No stirring
   • Expected Outcome: Given the solid cube form and lack of stirring, the dissolution rate is expected to be slow since solid cubes have a smaller surface area relative to powder. The temperature is favorable for dissolving, but without any stirring, the convection currents needed to distribute the soap molecules throughout the water will be minimal.

2. Heather

   • Form of soap: Powder
   • Water temperature: 105°C
   • Method of combination: Vigorous stirring
   • Expected Outcome: With a powdered form of soap, high temperature, and vigorous stirring, this method is likely the most effective for dissolution. The increased surface area of the powder allows for faster interactions with water molecules, and the high temperature enhances solubility.

3. Abdullah

   • Form of soap: Solid cube
   • Water temperature: 50°C
   • Method of combination: Gentle stirring
   • Expected Outcome: Similar to Darien, Abdullah is working with a solid cube of soap. However, gentle stirring may moderately assist in the dissolution process by improving the distribution of soap molecules compared to no stirring, although the overall rate is still likely to be slower than that of Heather's method.

4. Larissa

   • Form of soap: Powder
   • Water temperature: 75°C
   • Method of combination: Gentle stirring
   • Expected Outcome: Larissa's use of powdered soap at an elevated temperature will improve the dissolution compared to a solid cube. Gentle stirring, while less effective than vigorous stirring, will still help in dissolving the soap, although it may take longer than Heather's method.

Conclusion

Based on the methods and conditions described:

• Fastest Dissolution: Heather’s method (powder, high temperature, vigorous stirring) is expected to yield the quickest dissolution of soap in water.
• Moderate Dissolution: Larissa’s method will be effective but not as fast as Heather's due to the gentle stirring.
• Slowest Dissolution: Darien’s method will likely lead to the slowest dissolution due to the form of soap (solid cube) and the absence of stirring, although Abdullah's method may be slightly faster due to gentle stirring.

This experiment highlights the importance of combining different variables (form, temperature, and stirring) to optimize the dissolution process in a practical setting.