Hybridization And Thermodynamics

Question 1

valence bond theory resilts from what

Answer 1

the pairing of unpaired electrons in aromic orbitals

Question 2

single bond

Answer 2

sigma bond

Question 3

double bond

Answer 3

sigma bond and pi bond

Question 4

triple bond

Answer 4

sigma bond and 2 pi bonds

Question 5

cannot hybridize

Answer 5

terminal hydrogen or the halides

Question 6

electron promotion does not occur with nitrogen because

Answer 6

promotion would not increase the number of unpaired availabke for bonding

Question 7

pi bonds are

Answer 7

unhybridized px or py orbitals

Question 8

to determine the hybridization of an atom

Answer 8

of bonded atoms + # of lone pairs

Question 9

thermodynamics

Answer 9

deals with the energy change and sponteneity associated with a chemical reaction

Question 10

ΔHb (and charge)

Answer 10

▪bond enthalpy: it takes energy to break a bond

▪always pos

Question 11

ΔHr

Answer 11

enthalpy

Question 12

negative ΔHr

Answer 12

▪exothermic reaction

▪bonds stronger in products than reactants

Question 13

positive ΔHr

Answer 13

▪endothermic reaction

▪bonds stronger in reactants than products

Question 14

ΔHf

Answer 14

heat of formation

Question 15

when does ΔHf=ΔHr

Answer 15

when forming 1 mol of compounds from pure elements in their most stable form at standard state

Question 16

the sign of ΔG for a spontaneous reaction

Answer 16

negative

Question 17

Hess’s Law

Answer 17

if 2 or more chemical equations are added to give another equation, their corresponding ΔHr must be added

Question 18

spontaneous change

Answer 18

a process that, given enough time, occurs without the need for outside intervention

Question 19

entropy (s)

Answer 19

a measure of the disorder of a system

Question 20

ΔS is pos

Answer 20

imcrease in disorder

Question 21

ΔS neg

Answer 21

decrease in disorder

Question 22

increase in disorder =

Answer 22

increase in chance that a reaction is spontaneous

Question 23

standard temp

Answer 23

298K

Question 24

ΔGf measures

Answer 24

▪free energy of formation

▪a compunds stability relative to its elements

Question 25

ΔGf < 0

Answer 25

compound is thermodynamically stable relative to its elements

Question 26

ΔGf > 0

Answer 26

compound is thermodynamically unstable relative to its elements

Question 27

when ΔH is - and ΔS is +

Answer 27

spontaneous at all T

Question 28

ΔH + and ΔS -

Answer 28

nonspontaneous at all T

Question 29

ΔH + and ΔS +

Answer 29

spontaneous at high T and nonspontaneous at low T

Question 30

ΔH - and ΔS -

Answer 30

spontaneous at low T, nonspontaneous at high T