Semester 2 Final Review Part 2 Flashcards
(117 cards)
What is cohesion?
Attraction of liquid particles for each other
What is adhesion?
Attraction of liquid particles to particles of solid surfaces
Below the surface of a liquid, the particles are pulled?
Equally in all directions by cohesive forces
Surface particles are pulled only sideways and downwards because?
So they have a net downward force
Does it take energy to oppose net force and increase surface area?
Yes
What is surface tension?
The tendency of liquids to decrease surface area to the smallest size possible
A solid to a gas is called?
Sublimation
A gas to a solid is called?
Deposition
Does temperature change when a substance changes state?
No
It takes energy to overcome what?
The forces holding particles together
What is a good measure of the strength of the forces that hold particles together?
Boiling point and melting point
Do ionic substances have much higher forces of attraction than covalent substances?
Yes
Why do ionic substances have higher forces of attraction?
They are closer together
Compounds with smaller ions or bigger ions have the highest melting points?
Smaller ions because there are smaller distances between them
What are intermolecular forces?
Forces of attraction between molecules of covalent compounds
Are intermolecular forces weaker than the forces between atoms in the molecule?
Yes
What is a dipole?
One end of the molecule has a partial positive charge while the other has a partial negative charge
How will molecules orientate themselves in dipoles?
So that the opposite charges attract principle operates effectively
Is it true that very polar molecules have high dipole-dipole forces?
Yes
The more polar the molecules are,
The higher the boiling point of the substance
What is a special case of dipole-dipole interactions?
Hydrogen bonding
What is hydrogen bonding?
A hydrogen atom is bonded to a highly electronegative atom of one molecule which is attracted to two unshared electrons of another molecule
Is it true that compounds with hydrogen bonding have higher boiling points than comparable compounds?
Yes
When can a strong hydrogen bond form?
When a hydrogen atom is covalently bonded to very electronegative atoms in the upper-right part of the periodic table