In a laboratory experiment, students synthesized a new compound and found that when 10.17 grams of the compound were dissolved in 267.9 grams of benzene, the solution began to freeze at 4.952 °C. The compound was also found to be nonvolatile and a non-electrolyte.
In a laboratory experiment, students synthesized a new compound and found that when 10.17 grams of the compound were dissolved in 267.9 grams of benzene, the solution began to freeze at 4.952 °C. The compound was also found to be nonvolatile and a non-electrolyte.
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
Related questions
Question
![**Understanding the Freezing Point Depression Method to Determine Molecular Weight**
The freezing point of benzene, \( \text{C}_6\text{H}_6 \), is \( 5.500 \, ^\circ \text{C} \) at 1 atmosphere. The cryoscopic constant (\(K_f\)) for benzene is \(5.12 \, ^\circ \text{C/m}\).
In a laboratory experiment, students synthesized a new compound and found that when \(10.17\) grams of the compound were dissolved in \(267.9\) grams of benzene, the solution began to freeze at \(4.952 \, ^\circ \text{C}\). The compound was also found to be nonvolatile and a non-electrolyte.
**Question:**
What is the molecular weight determined for this compound?
**Details:**
- Mass of compound: \(10.17 \, \text{g}\)
- Mass of benzene: \(267.9 \, \text{g}\)
- Freezing point of pure benzene: \(5.500 \, ^\circ \text{C}\)
- Freezing point of solution: \(4.952 \, ^\circ \text{C}\)
- Cryoscopic constant (\(K_f\)) of benzene: \(5.12 \, ^\circ \text{C/m}\)
**Steps to Solve the Problem:**
1. Calculate the freezing point depression (ΔTf):
\[ \Delta T_f = T_f^\circ - T_f \]
where:
\[ T_f^\circ \] = freezing point of the pure solvent \[ (5.500\, ^\circ\text{C}) \]
\[ T_f \] = freezing point of the solution \[ (4.952\, ^\circ\text{C}) \]
2. Use the equation for freezing point depression:
\[ \Delta T_f = K_f \cdot m \]
where:
\[ K_f \] = cryoscopic constant \( (5.12\, ^\circ \text{C/m}) \)
\[ m \] = molality of the solution \(\left(\text{moles of solute} / \text{kg of solvent}\right)\)
3. Calculate the molality (m) of the solution:
\[ m = \frac{\Delta T_f}{K_f}](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F60358686-21d1-41ff-a93a-9ba59c7b6516%2Ff3c4ea14-eacd-42ae-9bcd-26de0bbff006%2Fxupch74.jpeg&w=3840&q=75)
Transcribed Image Text:**Understanding the Freezing Point Depression Method to Determine Molecular Weight**
The freezing point of benzene, \( \text{C}_6\text{H}_6 \), is \( 5.500 \, ^\circ \text{C} \) at 1 atmosphere. The cryoscopic constant (\(K_f\)) for benzene is \(5.12 \, ^\circ \text{C/m}\).
In a laboratory experiment, students synthesized a new compound and found that when \(10.17\) grams of the compound were dissolved in \(267.9\) grams of benzene, the solution began to freeze at \(4.952 \, ^\circ \text{C}\). The compound was also found to be nonvolatile and a non-electrolyte.
**Question:**
What is the molecular weight determined for this compound?
**Details:**
- Mass of compound: \(10.17 \, \text{g}\)
- Mass of benzene: \(267.9 \, \text{g}\)
- Freezing point of pure benzene: \(5.500 \, ^\circ \text{C}\)
- Freezing point of solution: \(4.952 \, ^\circ \text{C}\)
- Cryoscopic constant (\(K_f\)) of benzene: \(5.12 \, ^\circ \text{C/m}\)
**Steps to Solve the Problem:**
1. Calculate the freezing point depression (ΔTf):
\[ \Delta T_f = T_f^\circ - T_f \]
where:
\[ T_f^\circ \] = freezing point of the pure solvent \[ (5.500\, ^\circ\text{C}) \]
\[ T_f \] = freezing point of the solution \[ (4.952\, ^\circ\text{C}) \]
2. Use the equation for freezing point depression:
\[ \Delta T_f = K_f \cdot m \]
where:
\[ K_f \] = cryoscopic constant \( (5.12\, ^\circ \text{C/m}) \)
\[ m \] = molality of the solution \(\left(\text{moles of solute} / \text{kg of solvent}\right)\)
3. Calculate the molality (m) of the solution:
\[ m = \frac{\Delta T_f}{K_f}
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 2 images
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Recommended textbooks for you
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY