EXPERIMENT 5 (melting Point Determination)

Question 1

Defined as the temperature at which the liquid and solid phases are in equilibrium

Answer 1

Melting point of a solid

Question 2

___ of a liquid is the same temperature as the melting point of it’s solid

Answer 2

Freezing point

Question 3

Rarely measured in practice because they are more difficult to determine

Answer 3

Freezing point

Question 4

___ may not occur at the correct temperature due to the phenomenon of super cooling

Answer 4

Solidification

Question 5

Occurs when a liquid is cooled below its freezing point

Answer 5

Supercooling

Question 6

Can be done quickly with a small amount of sample in a capillary tube

Answer 6

Capillary melting

Question 7

Defined as the temperature range over which a small amount of solid in a thin walled capillary tube first visibly softens (first drop of liquid) and then completely liquefies

Answer 7

Capillary melting point

Question 8

A solid is said to melt ___ if the melting point range is ___ (narrow melting point range)

Answer 8

Sharply
0.5 - 1.0 °C

Question 9

At melting point a ___ will generally melt sharply because the forces of attraction between particles are the same.

Answer 9

Pure solid

Question 10

The presence of particles in a crystal lattice interrupts its uniform structure and the forces of attraction are ___

Answer 10

Weakened

Question 11

A ___ melts at a lower temperature and over a wide range

Answer 11

Impure solid

Question 12

A ___ is useful not only as an aid in identification but also an indication of purity

Answer 12

Solid melting point

Question 13

Tube used to determine the melting point

Answer 13

Capillary tube