Unit 4 Chemistry: Identification of Solvents and Solutes

Components of the Solution in Question 3

• The specific chemical mixture described in the problem consists of three primary components measured in different units of volume and mass:     - Water: A liquid component with a volume of $20\,\text{mL}$.     - Isopropyl Alcohol: A liquid component with a volume of $35\,\text{mL}$.     - Organic Solid: A solid component with a mass of $8\,\text{mg}$.

Theoretical Principles of Solvents and Solutes

• Definition of a Solvent: The solvent is the component of a solution that remains in the same phase as the solution itself and is present in the greatest amount (by moles, mass, or volume).
• Identification Criteria for Multi-Liquid Solutions:     - When multiple liquids are mixed to form a single-phase solution, the liquid present in the largest quantity is designated as the solvent.     - In this scenario, since the volume of isopropyl alcohol ($35\,\text{mL}$) exceeds the volume of water ($20\,\text{mL}$), isopropyl alcohol is scientifically classified as the solvent.
• Definition of a Solute: The solute is any substance in a solution that is dissolved by the solvent. A solution can contain multiple solutes.     - In this case, both the water ($20\,\text{mL}$) and the organic solid ($8\,\text{mg}$) are the solutes dissolved within the isopropyl alcohol.

Evaluation of Test Options

• Water: Though water is frequently termed the "universal solvent," in this specific concentration (where it constitutes only approximately $36.4\%$ of the liquid volume), it functions as a solute.
• Isopropyl Alcohol: This is the correct identification of the solvent because it represents the majority of the mixture's volume at $35\,\text{mL}$.
• Medication: The transcript menu options list "medication" as a potential answer, likely referring to the "organic solid." However, a solid dissolved in liquids is a solute, not a solvent.
• Water and Isopropyl Alcohol: This option suggests a co-solvent system. While mixed solvent systems exist in advanced chemistry, standard introductory chemistry defines the single component in the highest concentration as the primary solvent.
• "There is no solvent in this solution": This statement is false, as a homogeneous mixture (solution) by definition must contain at least one solvent.

Administrative Context and Metadata

• Assessment Title: Unit 4 Test.
• Educational Platform: TDSB eLearning Ontario (D2L/Brightspace).
• Progress Metrics:     - The test consists of at least $41$ total questions.     - The current question (Question 3) is located on page 3 of 41.     - At the time of the capture, $3$ of $41$ questions had been saved.
• Exam Duration and Timing:     - Time remaining on the exam clock: $1:20:23$.
• System State information:     - Ambient temperature or weather data indicated on the taskbar: $12^\circ\text{C}$.     - Current URL: tdsb.elearningontario.ca/d2l/lms/quizzing/user/attemp. (incomplete in screenshot).