kinetics and equilibrium

Question 1

kinetics

Answer 1

branch of chemistry concerned with eh rate of chemical reactions and the mechanics by which they occur

Question 2

elementary reactions

Answer 2

the series of steps that form a chemical reaction

Question 3

reaction mechanism

Answer 3

the complete sequence of elementary reactions; the step by step process by which reactants actually become products

Question 4

under what parameters does an effective collision of reactants occur

Answer 4

they must collide with minimum energy and proper orientation

Question 5

activation energy

Answer 5

the minimum amount of energy required to start a chemical reaction

Question 6

endothermic reaction speed

Answer 6

slow, bc requires a higher activation energy

Question 7

exothermic reaction speed

Answer 7

fast, bc requires lower activation energy

Question 8

combustion reactions are…

Answer 8

highly exothermic

Question 9

heat of reaction

Answer 9

• symbol is delta H
• either the overall heat absorbed or released in a reaction
• can be calculated by subtracting the enthalpies of the products - reactants

Question 10

another word for heat of reaction

Answer 10

enTHALPY

Question 11

Hess’s Law

Answer 11

the change in enthalpy is the same whether the reaction takes place in one step or a series of steps.

Question 12

what is the standard heat of energy for elements?

Answer 12

0

Question 13

an unstable compound will…

Answer 13

break down into simpler substances easily

Question 14

what table determines compound stability

Answer 14

Table I

Question 15

what kind of bond is strong?

Answer 15

Exothermic, because prods have low PE

Question 16

energy of formation

Answer 16

the same as energy of decomposition, but with the reverse sign

Question 17

reactions that break bonds tend to be _____ at room temperature

Answer 17

slow (endothermic)

Question 18

aqueous solutions react ____

Answer 18

quickly, the FASTEST kind of reaction is aq + aq

Question 19

how to increase rate of reaction between gases

Answer 19

increase pressure and thereby decrease volume

Question 20

ways to speed up reaction rates

Answer 20

• increase concentration
• increase temp (opposite if gas)
• (gas) increase pressure
• increase surface area

Question 21

catalyst

Answer 21

a catalyst lowers the activation energy in both the forward and reverse reactions equally, providing an ALTERNATE PATHWAY for the reaction
It recombines at the end of the reaction into its own compound again
sometimes causes two Activation Complex’s to form

Question 22

thermodynamics

Answer 22

allows to prediction of whether a process will occur but gives no info about the amount of time required

Question 23

delta G

Answer 23

gibb’s free energy change

Question 24

gibb’s free energy change

Answer 24

change in free energy between reactants and products in their standard state

Question 25

unit for heat of reaction

Answer 25

kJ/mol or kJ

Question 26

unit for entropy

Answer 26

kJ per K * mol

Question 27

unit for gibb’s free energy

Answer 27

kJ/mol r kJ

Question 28

entropy is an ____ property

Answer 28

extensive, therefore the # of moles must be taken into account

Question 29

a negative delta G =

Answer 29

spontaneous reaction

Question 30

what is the formula for gibb’s free energy

Answer 30

G = H - T*S