Unit 6 Flashcards
The attraction of the positive end of one molecule for the negative end of a neighboring molecule is a(n)
dipole-dipole force
For an exothermic reaction, the products
are at a lower energy level than the reactants
Enthalpy is the
energy of a system at constant pressure
The greater the kinetic energy of the particles in a sample of matter,
the higher the temperature is
Compared with a single gas, a mixture of gases is
more disordered
which of the following has a melting point greater than room temperature
iron
the enthalpy of a reaction for a chemical change can be determined by
subtracting the total enthalpy of the reactants from that of the products
Entropy decreases as a result of
a decrease in temperature
The Greek letter△ stand for
“change in”
In a cyclometer, the energy content of a substance is calculated from measurement of the temperature change in a known mass of
water
Pressure has an effect on boiling point because pressure affects
the entropy of a gas
A carbonated beverage over ice contains ___ phases
three
The study of all energy changes is called
thermodynamics
which depends only on the initial and final states of a reaction, rather than on the intermediate processes
both △H and △S
When particles are moving between two phases and no net change in the amount of either phase occurs, ___ exist(s)
equilibrium
The amount of energy needed to melt KCL is that compound’s
enthalpy of fusion
Compounds whose enthalpies of formation are highly negative
are very stable
A solid with a low melting point is most likely
covalent
A hydrogen bond forms between molecules that contain hydrogen bonded to
a highly electronegative atom
enthalpy changes accompanying a change of state are ___ than those accompanying the heating of a substance at each state
much larger
The strength of the forces between ions depends on
both the size of the ion and its charge
Natural events are often accompanied by a(n)
decrease in energy and an increase in disorder
Spontaneous reactions are driven by
decreasing enthalpy and increasing entropy
A London dispersion force is considered a dipole-dipole force because it
results from a temporary dipole
the topics covered by the study of thermodynamics include
both a and b
