Homework

# Solutions and Solubility

## Chapter 13: 1-2 Homework

Textbook assignment: Read Kotz and Triechel, Chemistry and Chemical Reactivity Chapter 13: Sections 1 and 2.

##### Study Notes
1. 13.1 Solubility solutions consist of a solvent and one or more solutes. When the solute is added to the solvent, the solute dissolves or separates into individual units. The number of solute particles per solvent molecule particles affect a number of properties, called colligative properties. We use a number of methods to indicate the ratio of solutes to solvents.
• Molality is the ratio of the amount of solute (in moles) to the mass of the solvent in kilograms.
• Molarity is the ration of the amount of solute in moles to the volume of the solution in liters.
• The mole fraction is the ratio of one substance in moles to the total number of moles of all substances in the solution.
• The weight percent is ration of the mass of one substance in kg to the mass of the total solution.

We use which ever measures appropriate for the circumstances.

2. 13.2 Creating solutions involves breaking apart the molecules of a chemical (solute) by the activity of a solvent. Two liquids are immiscible if neither can act as a solvent against the other. Like dissolves like: polar liquids dissolve other polar liquids and non-polar liquids dissolve other non-polar liquids. Non-polar and polar liquids tend to be immiscible when placed together. Dissolving chemicals is a reaction that can release or require energy (the heat of solution) to break apart a solid formation (lattice energy) and isolate the resulting molecules with solvent molecules (heat of hydration).

#### Key Formula

ConceptFormulaNotes
Molality Used for measuring colligative properties
Molarity Used for determining stoichiometric relationships/td>
Mole Fraction Used for comparing proportions of components in solution
Heat of solution

#### Web Lecture

Read the following weblecture before chat: Solutions and their Behavior

#### Videos for Chapter 13: Solutions and their Behavior

Review the Videos at Thinkwell Video Lessons.

• Under "Physical Properties of Solutions"
• Characterizing Solutions
• Types of Solutions
• Molarity and the Mole Fraction
• Molality
• Energy and the Solution Process

#### Interactive Exercise

Use the interactive exercise below to observe concentration changes when you vary the amount of solute and solvent.

#### Chat Preparation Activities

• Essay question: The Moodle forum for the session will assign a specific study question for you to prepare for chat. You need to read this question and post your answer before chat starts for this session.
• Mastery Exercise: The Moodle Mastery exercise for the chapter will contain sections related to our chat topic. Try to complete these before the chat starts, so that you can ask questions.

#### Chapter Quiz

• There is no chapter quiz YET.

#### (Aligns to) AP #10 GUIDED INQUIRY — Determination of solution concentration of copper sulfate solutions using visual colorimetry. — Phase I

Preparation: Use Java Applets to simulate spectroscope operation and identify the appropriate spectroscopy required to analyze vibrational or electronic motions. Lab design: Determine how you will create a reference set of standard solutions of copper sulfate. You will be using visual colorimetry methods to determine the relationship between transmittance, absorbance, and concentration of calibrated solutions.
• APGIE Lab 1: What is the Relationship Between the Concentration of a Solution and the Amount of Transmitted Light Through the Solution
• IGHCE Lab 7.5 Determine the Concentration of a Copper Sulfate Pentahydrate Solution through Visual Colorimetry
• HSCMK XIII-1: Determine Boron Concentration with Curcumin using Visual Colorimetry