Chapter U4.69, Problem 1E

Interpretation Introduction

Interpretation:

Difference between sugar melting and sugar dissolving in water must be described in words.

Concept introduction:

Melting is a physical change in which solid is converted to liquid. Dissolving in water is a physical change in which arrangements of atoms is broken due to incorporation of water molecules.

Answer to Problem 1E

  $\begin{array}{l}{C}_{12}{H}_{22}{O}_{11}\left(s\right)+heat\to C_{12}{H}_{22}{O}_{11}\left(l\right).\hfill \\ \hfill \\ C_{12}{H}_{22}{O}_{11}\left(s\right)+H_{2}O\left(aq\right)\to C_{12}{H}_{22}{O}_{11}\left(aq\right).\hfill \\ \hfill \end{array}$

Explanation of Solution

In metlting of sugar, the intermolecular force is decreased due to providing thermal energy. This results in increase in the intermolecular distance thus, solid sugar is converted to liquid sugar. But there is no involvement of water molecule.

In dissolving of sugar,the arrangement of atoms is destroyed. It means the crystal of sugar is broken as hydration energy overcomes the lattice energy.