exam four

Question 1

what is enthalpy?

Answer 1

sum of internal energy and the pressure/volume product of a system

Question 2

what does a positive ΔH indicate about a reaction?

Answer 2

endothermic

Question 3

what does a negative ΔH indicate about a reaction?

Answer 3

exothermic

Question 4

What are standard conditions?

Answer 4

25°C and 1 atm

Question 5

What does spontaneous mean?

Answer 5

will occur without the input of external energy

Question 6

what is entropy?

Answer 6

measure of randomness/disorder

Question 7

What is the ΔS of a system at equilibrium?

Answer 7

0

Question 8

What is the ΔS of a spontaneous process?

Answer 8

> 0

Question 9

If you decrease moles of gas, what happens to entropy?

Answer 9

decreases

Question 10

what is true of a reaction with a -ΔG?

Answer 10

spontaneous

Question 11

what is true of a reaction with a +ΔG?

Answer 11

nonspontaneous

Question 12

what happens when a substance is oxidized?

Answer 12

lose e-

Question 13

what happens when a substance is reduced?

Answer 13

gain e-

Question 14

what is the oxidation number of free elements in their uncombined state?

Answer 14

0

Question 15

what is the oxidation number of monatomic ions?

Answer 15

charge of ion

Question 16

what is the oxidation number of oxygen?

Answer 16

-2 (except in H2O2)

Question 17

what is the oxidation number of hydrogen?

Answer 17

+1 (except when bonded to metals in binary compounds… -1)

Question 18

what is the oxidation number of group 1A metals?

Answer 18

+1

Question 19

what is the oxidation number of group IIA metals?

Answer 19

+2

Question 20

what is the oxidation number of fluorine?

Answer 20

-1

Question 21

all oxidation number in a compound must add up to…

Answer 21

0

Question 22

Where does reduction occur?

Answer 22

at the cathode

Question 23

where does oxidation occur?

Answer 23

anode

Question 24

what connects two solutions?

Answer 24

salt bridge

Question 25

Do smaller or larger gas particles have a more entropy?

Answer 25

larger

Question 26

How is ΔS calculated?

Answer 26

ΔS=products-reactants

Question 27

what will always increase in a spontaneous process?

Answer 27

entropy of the universe

Question 28

what process will always be spontaneous (regardless of temperature)?

Answer 28

-ΔH and +ΔS

Question 29

A reaction is at equilibrium at any given temperature and contant pressure when...

Answer 29

ΔGrxn=0

Question 30

what two values are equal to zero when the system is at equilibrium?

Answer 30

ΔGsys and ΔSuniverse