Module 4 Intro

Module 4—Properties of Solutions

Module Introduction

Have you ever wondered why salt dissolves in water? Scientists approach such questions by studying the observable properties of a substance (also called empirical properties) and relating them to accepted scientific theories of the time.

According to Aristotle, an ancient Greek philosopher, all matter could be classified as fire, earth, air, and water. Aristotle reasoned that the dryness of salt makes it a kind of earth and that water acted on earth in a process similar to the way water erodes rocks.

In the 1800s, the scientific community generally accepted that small indivisible particles, called atoms, were the building blocks of matter. Using the concept of atoms, Svante Arrhenius was able to explain that the difference in conductivity between salt and sugar solutions is due to a phenomenon known as dissociation. In the 1900s electrons and intermolecular forces were known to chemists, so chemists were able to use these new ideas in their theories.

In this module you will explore the relationship between empirical properties and theoretical ideas, with an emphasis on qualitative and quantitative analysis.

Think about the following questions as you complete this module:

• What are some of your preconceived notions about solution chemistry?
  
  
• Have you acquired new knowledge from this module that contradicts your prior beliefs?