/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 5 You have read that adding a solu... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 11: Problem 5

You have read that adding a solute to a solvent can both increase the boiling point and decrease the freezing point. A friend of yours explains it to you like this: "The solute and solvent can be like salt in water. The salt gets in the way of freezing in that it blocks the water molecules from joining together. The salt acts like a strong bond holding the water molecules together so that it is harder to boil." What do you say to your friend?

Short Answer

Expert verified
In short, adding a solute to a solvent causes boiling point elevation and freezing point depression due to colligative properties. The solute particles interfere with the solvent particles' ability to escape into vapor, requiring more energy to boil the solution. Similarly, the solute disrupts the ordered arrangement of solvent particles during freezing, necessitating more energy to be removed for the solution to freeze. Your friend's explanation was partially correct but misunderstood the reason behind the boiling point elevation.

Step by step solution

01

Introduce Colligative Properties

Colligative properties are properties of solutions that depend on the ratio of the solute particles to the solvent particles. These properties include boiling point elevation and freezing point depression. It is important to note that these properties are independent of the nature of the solute, meaning that it doesn't matter if it's salt, sugar, etc.
02

Boiling Point Elevation

When a solute is added to the solvent, it increases the boiling point of the solution. This is because the solute particles interfere with the solvent particles' ability to escape into the vapor phase. Due to the solute particles presence, there are fewer solvent particles that can easily escape. Consequently, more energy (higher temperature) is needed for the solvent particles to overcome the attractive forces between them and become vapor. This increases the boiling point of the solution compared to the pure solvent.
03

Freezing Point Depression

Similarly, adding a solute to the solvent can decrease the freezing point of the solution. When a solute is added to a solvent, it causes disorder between the solvent particles. When the solution freezes, the solute particles get in the way of the solvent particles and disrupt the perfect arrangement of particles needed to form a solid. Therefore, more energy needs to be removed from the system (lower temperature) to overcome the disorder caused by the solute and allow the solvent particles to arrange themselves into a solid (frozen) state.
04

Address Your Friend's Explanation

Your friend's explanation is partially correct. It's true that the solute particles, like salt, get in the way of the water molecules forming a solid (freezing point depression); however, the part about the salt acting like a strong bond holding the water molecules together is not accurate. Instead, the salt (or other solutes) interferes with the water molecules ability to escape the solution, meaning that more energy is needed to boil the solution (boiling point elevation).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

How would you prepare \(1.0 \mathrm{~L}\) of an aqueous solution of sodium chloride having an osmotic pressure of \(15 \mathrm{~atm}\) at \(22^{\circ} \mathrm{C} ?\) Assume sodium chloride exists as \(\mathrm{Na}^{+}\) and \(\mathrm{Cl}^{-}\) ions in solution.

A solution of sodium chloride in water has a vapor pressure of \(19.6\) torr at \(25^{\circ} \mathrm{C}\). What is the mole fraction of solute particles in this solution? What would be the vapor pressure of this solution at \(45^{\circ} \mathrm{C} ?\) The vapor pressure of pure water is \(23.8\) torr at \(25^{\circ} \mathrm{C}\) and \(71.9\) torr at \(45^{\circ} \mathrm{C}\) and assume sodium chloride exists as \(\mathrm{Na}^{+}\) and \(\mathrm{Cl}^{-}\) ions in solution.

In some regions of the southwest United States, the water is very hard. For example, in Las Cruces, New Mexico, the tap water contains about \(560 \mu \mathrm{g}\) of dissolved solids per milliliter. Reverse osmosis units are marketed in this area to soften water. A typical unit exerts a pressure of \(8.0 \mathrm{~atm}\) and can produce \(45 \mathrm{~L}\) water per day. a. Assuming all of the dissolved solids are \(\mathrm{MgCO}_{3}\) and assuming a temperature of \(27^{\circ} \mathrm{C}\), what total volume of water must be processed to produce \(45 \mathrm{~L}\) pure water? b. Would the same system work for purifying seawater? (Assume seawater is \(0.60 \mathrm{M} \mathrm{NaCl}\).)

Calculate the normality of each of the following solutions. a. \(0.250 \mathrm{M} \mathrm{HCl}\) b. \(0.105 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\) c. \(5.3 \times 10^{-2} M \mathrm{H}_{3} \mathrm{PO}_{4}\) d. \(0.134 \mathrm{M} \mathrm{NaOH}\) e. \(0.00521 \mathrm{M} \mathrm{Ca}(\mathrm{OH})_{2}\) What is the equivalent mass for each of the acids or bases listed above?

In order for sodium chloride to dissolve in water, a small amount of energy must be added during solution formation. This is not energetically favorable. Why is \(\mathrm{NaCl}\) so soluble in water?
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Kinetics

Read Explanation

The Earths Atmosphere

Read Explanation

Chemical Reactions

Read Explanation

Chemical Analysis

Read Explanation

Chemistry Branches

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.