Temperature Measurements: Melting Points & Boiling Points Flashcards
What’s the freezing point of water?
0 C or 32 F
What’s the boiling point of water?
100 C or 212 F
T/F: Substances with higher vapor pressure evaporate faster than substances with low vapor pressure?
True
What’s an example of a substance w/ higher vapor pressure?
Gasoline
T/F: Liquids that evaporate more readily are called volatile.
True
What’s an example of a substance with lower vapor pressure?
Motor Oil
What’s the objective of this experiment?
Determine the melting and boiling points of known and unknown compounds!
Transitions: solid-to-liquid
Melting
Transitions: liquid-to-gas
Boiling
Melting point of a substance isn’t the same as freezing point?
False. It is the same!
What does the presence of an impurity do? (Melting Point)
Causes freezing point depression.
What does the presence of an impurity do? (Boiling Point)
Causes an increase in the boiling point.
Do some liquids decompose before their melting point and some decompose below their boiling points?
YES. Melting + Boiling points are NOT sufficient criteria to positively identify a substance. Compounds can have similar transition temperatures.
Are we looking for precise points or over narrow ranges of temperature?
Ranges.
What’s the labs objective?
Determine melting and boiling points of unknown and known compounds?
