14. Solutions

Molality

Water & Solutions - for Dirty Laundry: Crash Course Chemistry #7

Acetonitrile 1CH3CN2 is a polar organic solvent that
dissolves a wide range of solutes, including many salts.
The density of a 1.80 M LiBr solution in acetonitrile is
0.826 g>cm3. Calculate the concentration of the solution
in (a) molality,

Addition of 50.00 mL of 2.238 m H2SO4 1solution density
= 1.1243 g>mL2 to 50.00 mL of 2.238 M BaCl2 gives a white precipitate.
(b) If you filter the mixture and add more H2SO4 solution to the filtrate, would you obtain more precipitate? Explain.

What is the molality of the 40.0 mass % ethylene glycol 1C2H6O22 solution used for automobile antifreeze?

How to Calculate Molality

What's the Difference Between Molarity and Molality?

The density of acetonitrile 1CH3CN2 is 0.786 g>mL and
the density of methanol 1CH3OH2 is 0.791 g>mL. A solution is made by dissolving 22.5 mL of CH3OH in 98.7 mL of
CH3CN. (b) What is the molality of the solution?

Calculate the number of moles of solute present in each
of the following aqueous solutions: (b) 86.4 g of 0.180 m KCl,

Molality Concept 1

A solution is prepared by dissolving 20.2 mL of methanol
(CH3OH) in 100.0 mL of water at 25 °C. The final volume of the
solution is 118 mL. The densities of methanol and water at this
temperature are 0.782 g>mL and 1.00 g>mL, respectively. For
this solution, calculate the concentration in each unit.
b. molality

Describe how to prepare each solution from the dry solute and the solvent.
b. 125 g of 0.100 m NaNO3

Describe how you would prepare each of the following
aqueous solutions, starting with solid KBr:
(b) 125 g of 0.180 m KBr,

An aqueous NaCl solution is made using 112 g of NaCl diluted
to a total solution volume of 1.00 L. Calculate the molality of the solution. (Assume a density of
1.08 g>mL for the solution.)

Osmolality or Ionic Molality, represents number of dissolved particles in a solution.

Molality and Colligative Properties

Ethylene glycol, C2H6O2, is a colorless liquid used as auto-mobile antifreeze. If the density at 20 °C of a 4.028 m solu- tion of ethylene glycol in water is 1.0241 g/mL, what is the molarity of the solution? The molar mass of ethylene glycol is 62.07 g/mol

Molality Concept 2

Molality Example 1

A 0.944 M solution of glucose, C6H12O6, in water has a density of 1.0624 g/mL at 20 °C. What is the concentration of this solution in the following units?(c) Molality

Brass is a substitutional alloy consisting of a solution of
copper and zinc. A particular sample of red brass consisting of 80.0 % Cu and 20.0 % Zn by mass has a density of
8750 kg>m3. (a) What is the molality of Zn in the solid
solution?

Nalorphine 1C19H21NO3 2, a relative of morphine, is used to combat withdrawal symptoms in narcotics users. How many grams of a 1.3 * 10-3 m aqueous solution of nalor-phine are needed to obtain a dose of 1.5 mg?

Fluorocarbons (compounds that contain both carbon
and fluorine) were, until recently, used as refrigerants.
The compounds listed in the following table are all gases
at 25 °C, and their solubilities in water at 25 °C and 1
atm fluorocarbon pressure are given as mass percentages.
(a) For each fluorocarbon, calculate the molality of a saturated solution. 
Fluorocarbon Solubility (mass %)
CF4 0.0015
CClF3 0.009
CCl2F2 0.028
CHClF2 0.30

Molality Example 2

There’s actually much more in seawater than just dissolved NaCl. Major ions present include 19,000 ppm Cl-, 10,500 ppm Na+, 2650 ppm SO 2-, 1350 ppm Mg2+, 400 ppm Ca2+, 380 ppm K+, 140 ppm HCO3-, and 65 ppm Br-.
(a) What is the total molality of all ions present in seawater?

What's the Point of Molality?!?

Molarity vs. molality | Lab values and concentrations | Health & Medicine | Khan Academy

The density of a 15.7 M methanol (CH3OH) solution is 0.858 g/mL. If H2O is the solvent, what is the molality of the solution?

What is the ionic molality of sodium ions in a solution of 25.7 g NaNO3 dissolved in enough water to make a 150.0 mL of solution? Density of the solution is 1.02 g/mL.

Molarity, Molality, Volume & Mass Percent, Mole Fraction & Density - Solution Concentration Problems

An aqueous KNO3 solution is made using 72.5 g of KNO3 diluted
to a total solution volume of 2.00 L. Calculate the molality of the solution. (Assume a density of
1.05 g>mL for the solution.)

Ascorbic acid 1vitamin C, C6H8O62 is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved
in 210 g of water has a density of 1.22 g>mL at 55 °C. Calculate
(c) the molality,

A solution is prepared by dissolving 43.0 g potassium chlorate, KClO3, in enough water to make 100.0 mL of solution. If the density of the solution is 1.760 g/mL, what is the molality of KClO3 in the solution?

The figure shows two identical volumetric flasks containing
the same solution at two temperatures.
(b) Does the molality of the solution change with the
change in temperature? [Section 13.4]
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/8b790225cfb31d32-1666019546940.jpg" alt="" />

The density of toluene 1C7H82 is 0.867 g>mL, and the density of thiophene 1C4H4S2 is 1.065 g>mL. A solution is made
by dissolving 8.10 g of thiophene in 250.0 mL of toluene.
(b) Calculate the molality of thiophene in the solution.

A solution is made containing 20.8 g of phenol 1C6H5OH2
in 425 g of ethanol 1CH3CH2OH2. Calculate
(c) the molality of phenol.

Learn the toughest concepts covered in Chemistry with step-by-step video tutorials and practice problems by world-class tutors

Jules

General Chemistry

https://static.studychannel-prd.pearsonprd.tech/courses/general-chemistry/thumbnails/general-chemistry

#FFFFFF

The Organic Chemistry Tutor

CrashCourse

khanacademymedicine

Mr. Causey

Tyler DeWitt

Jules Bruno

Professor Dave Explains

1. Intro to General Chemistry

2. Atoms & Elements

3. Chemical Reactions

4. BONUS: Lab Techniques and Procedures

5. BONUS: Mathematical Operations and Functions

6. Chemical Quantities & Aqueous Reactions

7. Gases

8. Thermochemistry

9. Quantum Mechanics

10. Periodic Properties of the Elements

11. Bonding & Molecular Structure

12. Molecular Shapes & Valence Bond Theory

13. Liquids, Solids & Intermolecular Forces

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

Types of Aqueous Solutions

When an ionic solid dissolves, ions leave the solid and become dispersed in the solvent. Three possible aqueous solutions can be formed:saturated, unsaturated and supersaturated.

Boiling Point Elevation

Boiling Point Elevation is the phenomenon when adding a solute to a pure solvent results in increased boiling point of the solvent.

Intro to Henry's Law

According to&nbsp;Henry's Law, at a constant temperature the amount of a gas dissolved in a solvent is directly proportional to its partial pressure when it is in equilibrium with its liquid phase.&nbsp;

Osmotic Pressure

Osmotic Pressure is the force that drives Osmosis from higher concentration to lower concentration.

Mole Fraction

Mole Fraction (X) relates the moles of solute and solvent within a solution.&nbsp;

The Colligative Properties

The&nbsp;Colligative Properties&nbsp;explain what happens to a pure solvent as it transitions to a solution.

Molality (m)&nbsp;represents the number of moles of solute dissolved per kilogram of solvent.&nbsp;

Freezing Point Depression

Freezing Point Depression is the phenomenon when adding a solute to a pure solvent results in decreased freezing point of the solvent.

Solutions: Solubility and Intermolecular Forces

Solutions are homogeneous mixtures that result from the dissolving of a solute by a solvent.

Vapor Pressure Lowering (Raoult's Law)

Vapor Pressure is the pressure exerted by a gas at equilibrium with its liquid phase at a specific temperature in a closed system.

Henry's Law Calculations

To calculate solubility of a dissolves gas, Henry's Law Constant and partial pressure are used.

Solutions: Mass Percent

Mass Percent represents grams of solute per grams of solution, multiplied by 100.

Osmosis

Osmosis is the net movement of solvent across a semipermeable membrane.

Parts per Million (ppm)

<div dir="auto"><div contenteditable="true"dir="auto"spellcheck="true">Parts per Million (ppm) and Parts per Billion (ppb) are used to express extremely dilute solution concentrations.</div></div>

Study the key concepts of Physics with descriptive videos, questions, and more

Physics

Patrick

General Biology

Jason

Financial Accounting

Brian

Dive deep into Psychology with videos, practice problems, and more.

Psychology

Microeconomics

The first in a two-course sequence introduces the basic structure and functions of the human body

Anatomy & Physiology

College Algebra covers algebraic topics and skills necessary to succeed in college-level math

College Algebra

Organic Chemistry

Johnny

Genetics

Kylia

GOB Chemistry

Microbiology

Cell Biology

Analytical Chemistry

Study topics incliding trogonometric functions, identities and equations, solutions of triangles, complex numbers, and other topics as time permits

Trigonometry

Learn the toughest concepts covered in Precalculus with step-by-step video tutorials and practice problems by world-class tutors

Precalculus

Biochemistry

Macroeconomics

Chemistry

Biology

Math

Business

Social Sciences

Michelle Barry Franco

Building Great Presentations

Eric Zackrison, PhD

Critical Thinking And Problem Solving

Sam Bennett

Embracing Times Of Uncertainty

Nicole Tetreault, PhD

Emotional Intelligence Basics

Eugene Choi, PharmD

Enhancing Your Critical Thinking Skills

Jason Richardson, PsyD

Habits To Win Every Day

Alyssa Lowery, PhD

Having Powerful Advanced Conversations

Don Gilman, EdD

How To Influence & Persuade

Amy Matthews

Leadership Skills For Rising Stars

Listening To Lead

Michael Shermer, PhD

Making Decisions Under Uncertainty

Lynne Hurdle

Mistakes To Avoid When Resolving Conflict

Michael Veltri

Overcoming Decision Making Traps

Mike Vardy

Prioritizing Effectively

Secrets Of Effective Prioritization

Strategies To Build Up Your Creativity

Tools For Decision Making

Tutti Taygerly

Unleash And Advance Your Creativity

Winning Collaboration: How To Work More Effectively With Different Personalities

Writing Emails People Want To Read

Critical Thinking

Self Management

Digital Literacy

Collaboration

Communication

Analytical Thinking

Leadership

Flexibility/Adaptability

Innovation

Eric Zackrison

Nicole Tetreault

Dive deep into Python with videos and more.

Introduction to Python

Arianne Dee

Agile Project and Product Management

Agile & Product Management

Mariya Breyther 

Introduction to Microsoft Power BI

Microsoft Power BI

Chris Sorensen

Data Analysis Fundamentals with Excel

Data Analysis - Excel

Chris Sorensen & Ammul Shergill

Getting Started with  and Cryptocurrency

Introduction to Blockchain

George Levy

Learn Enough HTML, CSS and Layout to be Dangerous

HTML, CSS & Layout

Lee Donahoe & Michael Hartl

Learn Enough JavaScript to be Dangerous: A Tutorial Introduction to Programming with JavaScript

Introduction to JavaScript

Michael Hartl

R Programming

Jared P. Lander