Unit 6

Question 1

The attraction of the positive end of one molecule for the negative end of a neighboring molecule is a(n)

Answer 1

dipole-dipole force

Question 2

For an exothermic reaction, the products

Answer 2

are at a lower energy level than the reactants

Question 3

Enthalpy is the

Answer 3

energy of a system at constant pressure

Question 4

The greater the kinetic energy of the particles in a sample of matter,

Answer 4

the higher the temperature is

Question 5

Compared with a single gas, a mixture of gases is

Answer 5

more disordered

Question 6

which of the following has a melting point greater than room temperature

Answer 6

iron

Question 7

the enthalpy of a reaction for a chemical change can be determined by

Answer 7

subtracting the total enthalpy of the reactants from that of the products

Question 8

Entropy decreases as a result of

Answer 8

a decrease in temperature

Question 9

The Greek letter△ stand for

Answer 9

“change in”

Question 10

In a cyclometer, the energy content of a substance is calculated from measurement of the temperature change in a known mass of

Answer 10

water

Question 11

Pressure has an effect on boiling point because pressure affects

Answer 11

the entropy of a gas

Question 12

A carbonated beverage over ice contains ___ phases

Answer 12

three

Question 13

The study of all energy changes is called

Answer 13

thermodynamics

Question 14

which depends only on the initial and final states of a reaction, rather than on the intermediate processes

Answer 14

both △H and △S

Question 15

When particles are moving between two phases and no net change in the amount of either phase occurs, ___ exist(s)

Answer 15

equilibrium

Question 16

The amount of energy needed to melt KCL is that compound’s

Answer 16

enthalpy of fusion

Question 17

Compounds whose enthalpies of formation are highly negative

Answer 17

are very stable

Question 18

A solid with a low melting point is most likely

Answer 18

covalent

Question 19

A hydrogen bond forms between molecules that contain hydrogen bonded to

Answer 19

a highly electronegative atom

Question 20

enthalpy changes accompanying a change of state are ___ than those accompanying the heating of a substance at each state

Answer 20

much larger

Question 21

The strength of the forces between ions depends on

Answer 21

both the size of the ion and its charge

Question 22

Natural events are often accompanied by a(n)

Answer 22

decrease in energy and an increase in disorder

Question 23

Spontaneous reactions are driven by

Answer 23

decreasing enthalpy and increasing entropy

Question 24

A London dispersion force is considered a dipole-dipole force because it

Answer 24

results from a temporary dipole

Question 25

the topics covered by the study of thermodynamics include

Answer 25

both a and b