chemistry first examen

Que tipo de enlace es mas fuerte

ionic

ion dipole

when an ion and a nearby polar molecule(dipole), attract each other

dipole dipole force

the attractive forces that occur between the positive end of one molecule and the negative end of another polar molecule.

polar molecule

unequal distribution of charge that caues a partially positive and a partially negative end, leading to dipole characteristics.

Average Ek in a solid is lower

true

hydrogen bond

forms when the partially postive H of one molecule is attracted to the partially negative lone pair on the N, O or F of another molecule.

interacting particles ions present

ionic bonding, ion-dipole forces

interacting particles, ions not present

dipole-dipole forces, hydrogen bonding, dispersion forces

london dispersion forces

intermolecular force resposible for the condesed states of nonpolar substances. Present between all particles (atoms, ions and molecules) result from the motion of electrons in atoms. Instantaneous dipole-induced dipole forces.

intramolecular forces

bonding forces within each molecule. due to attraction between cations and anions(ionic bonding), nuclei and electron pairs(covalent bonding) or metal cations and delocalized electrons. it is chemical behavior.

intermolecular forces

between the molecules. The forces arise from attraction between molecules with partial charges or between ions and molecules , physical props

phase

each physical state, a physically distinct homogeneous part of a system

kinetic energy

the energy of motion of the particles in a subtance and is proportional to the absolute temp; the greater the kinetic energy of the particles at a particular temp, the greater their average speed

As temp increases, average kinetic

also does

exothermic changes

particles of a gas attract each other into a liquid, then become fixed in a solid, the system of a liquid, then becomes fixed in a solid, the system of particles loses energy, wich is released as heat

endothermic changes

heat must be absorbed by the system to overcome the attractive foces that keep the particles fixed in place in a solid or near each other in a liquid

enthalpy change fusion

6.01kJ/mol

enthalpy change vaporization

40.65 kJ/mol

enthalpy change sublimation

46.66kJ/mol

heating cooling curve

shows the changes in temperature of a sample when heat is absorbed or released at a constant rate

During a phase change

heat flow occurs at a constant temperature, which is associated with a change in average Ep, as the average distance between molecules changes.

Within a phase,

heat flow is accompanied by a change in temperature, which is associated with a change in average Ek, as the most probable speed of the molecules changes.