Question

use the information below to answer questions 13 - 16. a mixture of 4 substances can be separated in lab according to the flow chart below. the boiling point of water is 100°c. the boiling point of alcohol is 78°c. 13. based on the separation technique used, substance a must be ____. (a) magnetic (b) soluble in water (c) insoluble in water (d) insoluble in alcohol 14. what is the purpose of the final step involving substance d - boil at 78°c? this step... (a) allows the scientist to separate the alcohol from substance d by evaporating substance d. (b) allows the scientist to separate the alcohol from substance d by evaporating the alcohol. (c) removes excess water from the mixture that was added one step prior. (d) removes any additional impurities from the mixture.

Explanation:

Question 13

Step1: Analyze separation method

When water at \(30^{\circ}C\) is added and filtered, substance \(A\) is separated. Filtration separates insoluble solids from liquids.

Step2: Evaluate options

• Option A: Magnetic property is used in the first step (using magnet for substance \(C\)), not related to substance \(A\)'s separation here.
• Option B: If it were soluble in water, it would not be separated by filtration at this step.
• Option C: Since it is separated by filtration after adding water, it is insoluble in water.
• Option D: There is no information in the step of adding water and filtering (for separating \(A\)) about alcohol - solubility.

Question 14

Step1: Understand boiling - point separation

Substances can be separated by differences in boiling points. Alcohol has a boiling point of \(78^{\circ}C\).

Step2: Evaluate options

• Option A: Evaporating substance \(D\) would not separate alcohol. We want to keep substance \(D\) and remove alcohol.
• Option B: By boiling at \(78^{\circ}C\) (alcohol's boiling point), alcohol evaporates (boils off) and can be separated from substance \(D\) (which remains as a non - volatile or higher - boiling component).
• Option C: The previous step (boil at \(100^{\circ}C\)) is related to water (boiling point \(100^{\circ}C\)), not this step.
• Option D: There is no indication that this step is about removing additional impurities in a general sense; it is specifically about the alcohol - substance \(D\) separation based on boiling points.

Answer:

1. C. insoluble in water
2. B. allows the scientist to separate the alcohol from substance D by evaporating the alcohol