Chem Exam 3

Front 1

equation for Gibbs free energy

Back 1

∆G = ∆H - T∆S

Front 2

if ∆G is positive, then the reaction is...
(spontaneous, non-spontaneous, in equilibrium)

Back 2

non-spontaneous

Front 3

if ∆G is negative, then the reaction is...(spontaneous, non-spontaneous, in equilibrium)

Back 3

spontaneous

Front 4

if ∆G=0 then the reaction is (spontaneous, non-spontaneous, in equilibrium)

Back 4

in equilibrium

Front 5

a reaction is spontaeous at all temps if ∆H _ 0, and ∆S _ 0

Back 5

∆H < 0, ∆S > 0

Front 6

a reaction is nonspontaneous at all temps if ∆H_0, and ∆S_0

Back 6

∆H>0, ∆S<0

Front 7

a reaction is spontaneous at higher temps if ∆H_0, and ∆S_0

Back 7

∆H>0, ∆S>0

Front 8

a reaction is spontaneous at lower temps if ∆H_0, and ∆S_0

Back 8

∆H<0, ∆S<0

Front 9

uses a spontaneous reaction to generate electrical energy; system does work on the surroundings; all batteries use these

Back 9

voltaic cell (galvanic cell)

Front 10

uses electrical energy from an external power supply and converts lower energy reactants into higher energy products; surroundings do work on system; common in electroplating and recovering metals from ores

Back 10

electrolytic cell

Front 11

these conduct the electricity between the cell and the surroundings

Back 11

electrodes

Front 12

mixture of ions involved in the reaction

Back 12

electrolyte

Front 13

in a circuit, which way do electrons move?

Back 13

left to right

Front 14

in a circuit, which way do anions move?

Back 14

right to left

Front 15

in a circuit, which way do cations move?

Back 15

left to right through salt bridge

Front 16

In a spontaneous reaction, is Ecell positive or negative?

Back 16

positive

Front 17

the potential associated with a given half reaction when all components are in standard states; always refer to the half reaction written as reduction

Back 17

stnadard cell potential EoCell

Front 18

natural redox process that oxidizes metals to their oxides and sulfides

Back 18

corrosion

Front 19

Nerst equation

Back 19

Ecell = Eºcell - RT/ nF *lnQ

Front 20

the loss of an α particle from nucleus; A decreases by 4, Z decreases by 2

Back 20

alpha decay

Front 21

63/28 Ni -> 63/29 Cu + 0/-1 β

Back 21

beta decay

Front 22

11/6 C -> 11/5 B + 0/1 β

Back 22

positron decay

Front 23

55/26 Fe + 0/-1 e -> 55/25 Mn + h(x-ray)

Back 23

electron capture

Front 24

238/92 U -> 234/90 Th + 4/2 He + 2 0/0γ

Back 24

gamma emission

Front 25

the ration of neutrons to protons that determines stability

Back 25

N/Z ratio

Front 26

all nuclides with Z>83 are

Back 26

unstable

Front 27

nuclides with too many neutrons for stability lie above the band of stability and exhibit which type of decay

Back 27

neutron rich nuclide; beta decay

Front 28

nuclides with too few neutrons for stability lie below the band and exhibit which type of decay

Back 28

neutron poor nuclide; positron decay or electron capture

Front 29

when Z>83, the nuclides lie within the band and undergo which type of decay

Back 29

heavy nuclides; alpha decay

Front 30

uses radioisotopes to determine the age of an object; based on amount of 14C and 12C in materials; the different between 14C:12C in dead organisms and the ratio in living organisms reflects time elapsed since organism died

Back 30

radioisotopic dating

Front 31

radiation of relatively low energy interacts with an atom of a substance, which absorbs some of the energy and then re-emits it

Back 31

excitation

Front 32

causes excitation

Back 32

nonionizing radiation

Front 33

heavy nucleus splits into 2 much lighter nuclei emitting several small particles at the same time

Back 33

fission

Front 34

opposite process of fission; occurs as 2 lighter nuclei combine to form heavier one

Back 34

fusion