Question

Define lower end and upper end of a melting point range. (Select all that apply)

O The lower end is the temp at which liquid first appears.
O The upper end is the temp at which liquid first appears.
O The upper end is the temp at which the last trace of crystals disppears.
O The lower end is the temp at which the last trace of crystals disppears.

Answer 1

• The lower end is the temp at which liquid first appears
• The upper end is the temp at which the last trace of crystals disappear

Step-by-step explanation:

Melting range is one of the properties of solid that can help to identify its purity. It is necessary to note the whole range of temperature through which the transition takes place. The change in this range of melting temperature is indicative of impurity in the sample.

The lower end is the starting temperature at which solid starts to melt while the upper end is the temperature at which the last trace of solid converts to liquid.