Chapter U2.15, Problem 2E

Interpretation Introduction

Interpretation : Intermolecular attractions are to be explained.

Concept Introduction :

There are two classes of molecules; polar and nonpolar. Polar molecules are attracted by a charged wand whereas a nonpolar molecule is not attracted by a charged wand. Examples of polar molecules: water, vinegar, rubbing alcohol and that of non-polar molecules is oil, methane, etc.

Answer to Problem 2E

A polar molecule is a molecule that possesses partial charges on its atoms. There is a partial positive and a partial negative charge on atoms. The partial charges on polar molecules also cause attractions between molecules. This attraction between molecules is called intermolecular force of attraction.It causes molecules to bind together.

Explanation of Solution

A polar molecule is one which has a partial positive charge on one side and partial negative charge on other side of the molecule.

When a charged wand is brought near a liquid like water, it attracts the stream of water. This is due to polarity in water molecules. Due to this the hydrogen atoms orient themselves towards the negatively charged wand and the whole stream of water gets attracted towards the wand.

The partial charges on polar molecules not only cause attraction to a charged wand but also cause attraction between molecules. The molecules tend to align with each other because partial negative charges are attracted to partial positive charges. This attraction between molecules is called intermolecular force of attraction.