unit 6 1-10 Flashcards
Explain which have stronger intermolecular forces, Hydrogen bonds or London Dispersion forces.
Hydrogen bonds have stronger forces because of its electrostatic properties and London’s dispersion is more general and arises from temporary fluctuation in electrons.
What can bond with Hydrogen bonds.
If it is already bonded to an atom such as c it complete, but it can bond with N, n, o, F.
Can a bond be polar within a molecule that is nonpolar. Explain.
Yes, because the arrangement and geometry determines overall polarity, so polar bonds can reside inside but the overall distribution of the charge can make it nonpolar.
Why are London Dispersion forces the only forces of attraction between nonpolar molecules?
They are the only forces because they lack permanent dipoles that result in no electronegativity, this means no other forces can happen.
The nonpolar molecules are neutral.
Use the kinetic theory to explain what causes gas pressure.
Gas pressure is made from the collisions between particles and the walls.
Explain the relationship between the Kelvin temperature of a substance and the kinetic energy of its particles.
As the temperature increases the particles store some and excite more, so as temp rises so does the kinetic energy.
What factors help determine the physical properties of liquids?
Temperature, intermolecular forces, molecule size and shape.
Explain why liquids and gases differ in density and the ability to be compressed.
Since there is open space in gas molecules that results in a lower density, The same empty space between is the reason that gasses are easily compressed because the particles get pushed together, gasses lack the attractive forces liquids have.
Describe what is happening at the molecular level when a dynamic equilibrium occurs.
The particles are condensing and will equal the particles that are vaporizing.
Describe the effect that increasing temperature has on the vapor pressure of a liquid.
Increasing the temp will cause the energy to speed which lets more particles escape their forces to escape the liquid, this causes there to be more gaseous space in a container making more vapor pressure.
What conditions must exist for a substance to boil?
The temperature is equal to the vapor pressure of the liquid is just equal to the external pressure on the liquid.
Explain the dynamic equilibrium between evaporation and condensation.
The particles condensing equal the particles vaporizing, overall there is no net charge of particles changing.
Explain why molecular solids usually have lower melting points than ionic solids.
The intermolecular forces are weaker so require less energy to change states.
What is the difference between a unit cell and a crystal lattice?
The crystal lattice represents the overall arrangement, while the unit cell is about a repeating fundamental unit.
How do allotropes of an element differ?
The physical properties, chemical properties, crystalline structure, bonding arrangements and number of atoms.
