Things you need to know FOR the final Flashcards

1
Q

What is thermochemistry?

A

The study of Enthalpy(head) changes om a chemical reaction that walways involves a system + surroundings to create.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the types of systems?

A

Open, Closed and Isolated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Temperature in thermochem?

A

Celcius or Kelvins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens in an Open System?

A

Mass and energy are exchanged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is enthalpy?

A

Heat flow measured under conditions of constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens in an Isolated System?

A

Neither are exchanged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens in a Closed System?

A

Only energy is exchanged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are thermochem units?

A

Temperature, Heat, Enthalpy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Heat in thermochem?

A

is Q and is in Joules/ Kilojoules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Enthalpy in thermochem?

A

Is H and is also in Joules/ Kilojoules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a spontaneous process?

A

A process that occurs in a system left to itself. It does not mean that it is fast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

1st law of energy flow is?

A

When energy can be converted from one form to another, but cannot be created/destroyed (ice to water, water to gas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do downhill reactions mean?

A

Exothermic, it is giving off heat and causing the temp to go up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do uphill reactions mean?

A

Endothermic, is absorbing heat and is causing the temp to go down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

2nd law of energy flow is?

A

Explains why chem reactions who in a certain direction. It is based on entropy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Whats more spontaneous, gas or liquid?

A

Gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Whats more spontaneous, solid or liquid?

A

liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Whats more spontaneous, gas or solid?

A

gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How to calculate ΔS of rxn?

A

Products - Reactants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the second law of Entropy?

A

The entropy of the universe increases in a spontaneous process and remains unchanged in an equilibrium process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Equilibrium in entropy?

A

ΔSuniv = ΔSsys +ΔSsurr = 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Spontaneous reactions in Entropy?

A

ΔSuniv(+)= ΔSsys(-)+ΔSsurr(+)>0

14
Q

How to calculate ΔSsurr?

A

-(ΔHsys)
———–
T

15
Q

How to calculate ΔG?

15
How to calculate ΔH from ΔHf?
(Products-reactants) *(# of moles)
16
Spont., Nonspont., or Temp dependent?: ΔH(enthalpy)= - ΔS(entropy)= - ΔG= +
Spontaneous, but only at low temperatures
16
Spont., Nonspont., or Temp dependent?: ΔH(enthalpy)= - ΔS(entropy)= + ΔG= -
Always spontaneous
16
How to calculate ΔS?
(Products-reactants) *(# of moles)
16
Spont., Nonspont., or Temp dependent?: ΔH(enthalpy)= + ΔS(entropy)= - ΔG= +
Always nonspontaneous
17
Spont., Nonspont., or Temp dependent?: ΔH(enthalpy)= + ΔS(entropy)= + ΔG= -
Spontaneous, but only at high temperatures.
17
How to find T when given ΔH and ΔS?
ΔH/ΔS
17
What is the second way to find ΔG?
ΔG of rxn= Sum of all Products - Sum of all Reactants or final-initial
17
How to calculate ΔSvap?
ΔHvap --------- Tb
18
How to find T if given ΔHfus and ΔSfus?
ΔHfus/ ΔSfus
18
How to calculate ΔSfus?
ΔHfus -------- Tm
18
How to calculate reaction rate?
Change in # of moles/ Change in time
19
What variables affect rate?
The type of reaction it is, Concentration, time, temp, pressure/volume, a catalyst or the lack of one.
20
If ΔG is large and negative what must be true?(When ΔG< 0)
Products are favored at equilibrium and is Spontaneous
20
If ΔG is small and positive what must be true? (When ΔG> 0)
Is nonspontaneous and reactants are favored
21
Rate law for a first order reaction?
Rate=k[A]
22
Rate law for a second order reaction?
Rate=k[A]^2 or Rate=k[A][B]
23
Rate law for a 0 order reaction?
Rate=k
23
Integrated rate law for 2nd order reaction graph info?
Will be 1/[A]t by time and is pointed up from left to right
23
Integrated rate law for 1st order reaction?
ln([A]t/[A]0)=-kt
24
Integrated rate law for 1st order reaction graph info?
will be ln[A]t by time, is pointed down from left to right
24
Integrated rate law for 1st order reaction?
ln[A]t=-kt+ln[A]0
25
Integrated rate law for 2nd order reaction?
1/ln[A]t=kt+1/ln[A]0
26
Integrated rate law for 0 order reaction?
[A]t=-kt+[A]0
27
What does [A]0 stand for?
Concentration at the initial time or at time of 0
27
Integrated rate law for 0 order reaction graph info?
Will be [A]t by time and is pointed down from the left to the right.
28
What does [A]t stand for?
Concentration at that specific time.
29
How to find rate in general?
change in [A]/ change in time
30
what does k =?
rate constant