Solutions of Nonelectrolytes Overview

Questions and Answers

What is the primary use of a refractometer?

To measure electrical resistance

To measure mass

To measure refractive index (correct)

To measure boiling point

Which of the following is NOT categorized as an extensive property?

Volume

Mass

Enthalpy

Density (correct)

What defines a colligative property?

It defines the solute-solvent interaction

It depends on temperature changes

It depends on the type of substance present

It depends on the number of components in the system (correct)

Which of the following is an example of a colligative property?

Vapor pressure lowering Signup and view all the answers

What is the particle size range for colloidal dispersions?

1 nanometer to 0.5 micrometers Signup and view all the answers

Which of the following is considered an intensive property?

Temperature Signup and view all the answers

How are extensive properties differentiated from intensive properties?

Extensive properties change with changes in size or amount Signup and view all the answers

Which of the following types of dispersion has the largest particle size?

Coarse dispersion Signup and view all the answers

What defines a solution in terms of its composition?

A chemical and physically homogeneous mixture of 2 or more substances. Signup and view all the answers

Which of the following is NOT a type of concentration expression discussed?

Specific gravity Signup and view all the answers

What is the correct term for the combined properties of individual components in a system?

Additive property Signup and view all the answers

What characterizes a constitutive property in a system?

It depends on the type and arrangement of components. Signup and view all the answers

Which of the following is an example of a one-phase system?

True solutions Signup and view all the answers

How is molecular weight computed for sodium chloride?

By finding the individual atomic weights of sodium and chlorine and adding them together. Signup and view all the answers

What property is measured using a polarimeter?

Optical rotations Signup and view all the answers

Which term describes two or more phases in a system?

Heterogeneous system Signup and view all the answers

What characterizes a saturated solution?

It has the maximum quantity of solute dissolved at a given temperature. Signup and view all the answers

In the context of solutions, what is a solvent?

The component that is usually present in a greater amount and dissolves the solute. Signup and view all the answers

Which solution type contains both ions and molecules separated in a solution?

True solution Signup and view all the answers

Which of the following correctly defines a non-electrolyte?

A substance that does not ionize when dissolved in water. Signup and view all the answers

What occurs in a supersaturated solution?

It has more solute than can be dissolved at that temperature. Signup and view all the answers

Which of the following components is likely considered a solute in the mixture of water and coffee?

Coffee grounds Signup and view all the answers

Which characteristic of ionic compounds contributes to their solubility in water?

Their ability to ionize due to polar interactions. Signup and view all the answers

What is the primary reason that potassium permanganate dissolves in water?

It ionizes into potassium and permanganate ions. Signup and view all the answers

What is the formula for calculating molarity?

Moles of solute divided by liters of solution Signup and view all the answers

How is the number of moles of a solute calculated from its weight and molecular weight?

Weight divided by molecular weight Signup and view all the answers

If you have 5 grams of nickel(II) chloride hexahydrate, what is the molecular weight used for calculating moles?

237.7 grams Signup and view all the answers

What is the molarity of a solution made by dissolving 5 grams of nickel(II) chloride hexahydrate in enough water to make 250 mL?

0.08 molar Signup and view all the answers

What unit is used for expressing molarity?

Moles per liter Signup and view all the answers

What does normality measure in a solution?

Gram equivalent weight of solute in a liter of solution Signup and view all the answers

What is the mass required to make a 0.05 molar solution in 250 mL of oxalic acid (H2C2O4)?

2.5 grams Signup and view all the answers

How is molality defined?

Moles of solute per kilogram of solvent Signup and view all the answers

What is the weight in grams per liter for a 1% weight by volume solution?

10 grams per liter Signup and view all the answers

How is osmolarity calculated for a solution containing aluminum sulfate?

Weight in grams per liter divided by molecular weight times number of species times 1,000 Signup and view all the answers

What is the molecular weight of calcium chloride?

111 g/mol Signup and view all the answers

What is the correct calculation for the osmolarity of a 100 grams per liter calcium chloride solution?

100 divided by 111 times 3 Signup and view all the answers

What is the mole fraction of sodium chloride in a solution with 1 mole of NaCl and 100 grams of water?

0.982 Signup and view all the answers

To find the mole fraction of water in the same solution, which calculation is used?

Moles of water divided by total moles of solute and solvent Signup and view all the answers

How many milliosmoles per liter does a complete ionizing solution of aluminum sulfate yield?

83.83 milliosmole per liter Signup and view all the answers

Which formula correctly represents the calculation of the mole fraction of sodium chloride?

Moles of sodium chloride divided by the sum of moles of sodium chloride and moles of water Signup and view all the answers

Study Notes

Solutions and Concentrations

Definition of Solution: A homogeneous mixture of two or more substances, comprising a solute and a solvent.
Learning Objectives: Students should demonstrate knowledge of solution concentrations and solve related problems.

Types of Systems

System: A specified quantity of material or a bounded space.
One-Phase System: True solutions, characterized by molecular dispersion.
Two or More Phase System: Includes coarse and colloidal dispersions.

Physical Properties of Systems

Additive Property: Depends on the sum of individual properties (e.g., molecular weight).
Constitutive Property: Depends on the type/arrangement of components (e.g., optical rotation measured by polarimeter).
Colligative Property: Depends on the number of components; includes vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure lowering.

Types of Properties

Extensive Properties: Depend on size/amount in the system (e.g., mass, volume).
Intensive Properties: Do not depend on size/amount (e.g., density, temperature).

Dispersion

Definition: Consists of at least two phases with one or more dispersed internal phases in a continuous external phase.
Types of Dispersions:
- Molecular Dispersion (True Solution): Particle size <1 nm.
- Colloidal Dispersion: Particle size from 1 nm to 0.5 µm.
- Coarse Dispersion: Particle size >0.5 µm.

Definitions of Solutions

Solution: A homogeneous mixture of solute and solvent.
Saturated Solution: Contains maximum solute quantity at a given temperature.
Unsaturated Solution: More solvent than solute.
Supersaturated Solution: More solute than can normally dissolve.

Classification of Solutes

Nonelectrolytes: Substances that do not ionize in water.
Electrolytes: Substances that do ionize in water, often ionic compounds.

Concentration Expressions

Molarity (M): Moles of solute per liter of solution.
Molality (m): Moles of solute per kilogram of solvent.
Normality (N): Equivalent weight of solute per liter of solution.

Example Calculations

Molarity Example: If 5 grams of nickel(II) chloride hexahydrate is dissolved in enough water to make 250 mL of solution, it is calculated as 0.08 M.
Osmolarity Calculation: For aluminum sulfate in solution, ionization leads to calculations of milliosmoles based on molecular weight and number of ions produced.

Mole Fraction

Mole Fraction Calculation: Mole fraction of a solute is calculated using the formula:
- Mole fraction = moles of solute / (moles of solute + moles of solvent).
Example Calculation: For 1 mole of sodium chloride in 100 grams of water, calculate the mole fraction of sodium chloride.

Assignments and Practice Problems

Engage with practice problems to solidify understanding of molarity, molality, normality, and mole fractions.
Familiarize with calculations of osmolarity based on concentration and complete ionization of substances.

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Description

This quiz covers the concepts related to solutions, specifically focusing on nonelectrolytes. Students will learn about the definitions of solute and solvent, as well as the characteristics of homogeneous mixtures. It aims to enhance understanding of chemical mixtures and their properties.