Lab 1: Intermolecular Forces Flashcards
Purpose
Investigate relationship of dispersion forces and hydrogen bond forces
When does evaporation occur in experiment?
When probe is removed from liquid’s container
What kind of process is evaporation?
Result?
Endothermic process
Results in temperature decrease
What is magnitude of temperature decrease related to?
Strength of IMF of attraction between molecules
In this experiment, study what and related to what?
Temperature changes caused by the evaporation of several liquids
and relate temperature changes to strength of IMF of attraction
Liquids with weaker intermolecular forces
Temperature change is greater because there is greater evaporation
Two types of organic compounds in experiment
Alkanes and Alcohols
Two alkanes
Pentane (C5H12) and Hexane (C6H14)
Alcohols contain what
-OH functional group, + carbon and hydrogen atoms
Two alcohols
Methanol (CH3OH) and Ethanol (C2H5OH)
Examine molecular structure of alkanes and alcohols for what
Presence and relative strength of two IMF: hydrogen bonding and dispersion forces
Dispersion forces and increase as
Exist between any two molecules
Generally increase as the molecular weight of the molecule increases
Hydrogen bond
Can occur when a molecule has a hydrogen atom bonded directly to N, O, or F atom (the donor) and that hydrogen is attracted to a lone pair on an N, O, or F atom in another molecule (the acceptor)
What must be present for a hydrogen bond to occur
Both a donor and acceptor
