gen Chem page 4

Question 1

first law of thermo

Answer 1

delta U= Q-W
Q is heat added
-W is work done by system
+W is work done to system

Question 2

heat transfer no phase change

Answer 2

q=mc delta T (use C or K)

Question 3

heat transfer during phase change

Answer 3

q=mL

L is latent heat like H vap H fusion

Question 4

generalized enthalpy of reaction

Answer 4

delta H rxn= H products - H reactants

unit is Kj/mol

Question 5

standard enthalpy of reaction

Answer 5

delta H rxn= sum of (delta Hf products- delta Hf reactants)

Question 6

bond enthalpy

Answer 6

delta H rxn= delta H bonds broken- delta H bonds formed

total energy absorbed- total energy released

Question 7

entropy

Answer 7

delta S= Q rev/T

unit J/K

Question 8

second law of therm

Answer 8

delta S universe= delta S system + delta S surroundings >0

Question 9

standard entropy of reaction

Answer 9

delta S rxn= sum of (delta S, f products - delta S, f reactants)

Question 10

gibbs free energy

Answer 10

delta G=delta H- TdeltaS

Question 11

+ H and + S

Answer 11

spontaneous at high temps

Question 12

-H and -S

Answer 12

spontaneous at low temps

Question 13

-H and + S

Answer 13

• G (spontaneous)

Question 14

+H and -S

Answer 14

+G (nonspontaneous)

Question 15

standard gibbs free energy of reaction

Answer 15

delta G rxn= sum of (delta G, f products- delta G, f reactants)

Question 16

standard gibbs free energy from eq constant

Answer 16

delta G rx= -RT ln Keq

Question 17

gibbs free energy from reaction quotient

Answer 17

delta G (not standard)= delta G rxn std + RT ln Q= RT ln Q/Keq

Question 18

isothermal

Answer 18

Q=W and curve is hyperbolic (P on y axis and V on x)

Question 19

adiabatic

Answer 19

no heat exchange
delta U=-W
also hyperbolic like isothermal

Question 20

isobaric

Answer 20

same pressure

horizontal line

Question 21

isovolumetric or isochoric

Answer 21

delta U= Q

vertical line

Question 22

specific heat for water

Answer 22

1 cal/gK or 4.2 J/gK

or C instead of K

Question 23

heat capacity=

Answer 23

mc

Question 24

state functions

Answer 24

path independent

under Pressure and feeling Dense all I want is to watch TV and get HUGS

Question 25

water has a unique P vs T phase diagram because

Answer 25

density of ice is less than density of water.

Question 26

triple point

Answer 26

where all lines meet- all phases in equil

Question 27

critical point

Answer 27

at end of gas/liq line where phase boundaries vanish and gas and liquid coexist

Question 28

STP

Answer 28

273 K

Question 29

standard temp

Answer 29

298 K