Definitions Flashcards
(96 cards)
1
Q
Reaction Rate:
A
Reaction Rate:
the speed at which a chemical reaction proceeds.
2
Q
Endothermic:
A
Endothermic:
Heat is added; ENters the object, by adding heat, a reaction will go faster.
3
Q
Exothermic:
A
Exothermic:
The loss of heat/energy from a species; Exits the object. e.g.) water=>ice, freezer will take away, freezer will take away heat energy creating a solid.
4
Q
Entropy:
A
Entropy:
(s) the lack of order/organization/symmetry in the compound. It is the level of chaos in the compound. As entropy increases, chaos will also increase. (second law of thermodynamics)
5
Q
Enthalpy:
A
Enthalpy:
objects spontaniously seek the lowest energy state possible within a given system. (for spontaneous situations = negative enthalpy) Enthalpy has two special terms related to it; endothermic and exothermic.
6
Q
What makes a chemical reaction ‘spontaneous’?
A
- A spontaneous reaction happens without any outside intervention, without any addition of energy. (nothing forces it to occur)
- A spontaneous reaction may either be slow or fast.
- Entropy and enthalpy are two factors that affect spontaneity.
- Second law of thermodynamics => for any spontaneous chemical reaction, the overall (s) must be greater or equal to zero; but spontaneous chemical reaction can still have a result
7
Q
What type of spontaneous reactions normally occur?
A
exothermic
8
Q
What are common ways in which reaction rate are empirically measured?
A
- measuring change in gas production (only works if there is a gas produced)
- Measuring the concentration or ion production (using electricity) This method works for reaction that occur in a solution and produce Ions
- Measure the production of colour using a colorimeter (electronic measuring device)
9
Q
What are “5” factors that affect a reaction rate?
A
- Nature of reactants
- Concentration of reactants
- Temperature
- Catalyst
- Surface area
10
Q
How is the instantaneous reaction rate found from a concentration versus time graph?
A
It can be found using slope
average = (concentration/time)
instantaneous = tangent
11
Q
rate law
A
rate forward = k[A]^a x [B]^b
12
Q
zero order reaction
A
the concentration of the species has no effect on the reaction rate
13
Q
first order reaction
A
a change in the species concetration causes the same proportional change in reaction rate
14
Q
second order reaction
A
a change in the species concentration causes (proportional change)^2 in reaction rate
15
Q
overall order of reaction
A
sum of all the orders of reaction
16
Q
Robert Boyle’s Scientific method
A
Data, Graph, Re-graph to produce linear graph, equation using y=mx+b
17
Q
Integrated Rate laws
A
zero: [A]=-kt+[A]i
First: ln[A] =-kt+ln[A]i
Second: 1/[A]=-kt+1/[A]i
18
Q
Radioactivity
A
like carbon 14 decay, and medical isotopes, follow the 1st order of decay with a constant half-life regardless of amount present.
19
Q
Collision theory
A
1: a chemical system consists of particles in random motion at various speeds. The Avg KE is proportional to temp
2. A chemical reaction must involve collisions of particles
3. An effective collision is one that has sufficient energy and correct orientation so bonds can break and new ones formed
4. Ineffective collisions involve particles that rebound from collision, changed in nature
5. The rate of a collision depends on the frequency of collisions and the fraction of those collisions that are effective
20
Q
what is the rate determining step?
A
The slowest elementary step in a reaction
21
Q
Elementary Step
A
on step in a complete reaction that involves 3 or less particles. Only one collision
22
Q
Intermediate
A
chemical species that are produced in one elementary step and consumed in another. (Sit in the troughs of graphs)
23
Q
3 Types of Equilibrium
A
Solubility: eq between rate of dissolving and rate of precipitating
Phase Equilibrium: Eq between opposing phase change rates
Chemical Equilibrium: Eq between forward rate of reaction and reverse rate of reaction
24
Q
How can you tell when a graph reaches EQ
A
the concentration of reactants and products plateau
25
What must happen for a solubility EQ to occur
solution must be saturated and the system must be closed
26
Quantitative
+99% reaction
27
Product favoured
>50% and <99%
28
neither favoured
50%
29
reactant favoured
<50% and >1%
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No reaction
<1%
31
% reaction
Actual Yield/theoretical max yield x100
32
K equation
k= [C]^c x [D]^d/[A]^a x [B]^b
33
Limitations of K
k will change if surface area, temperature, catalyst or nature of reactant change
K does not include solid or liquid
34
Le chatelier's Principle
if a system at equilibrium is disturbed, the system will move to restore equilibrium
35
3 ways to disturb an equilibrium
change concentration, change temperature, change pressure
36
What happens if we change pressure on a system
If we increase pressure the system will respond to reduce the pressure by shifting to the side with less moles of gas. and vice versa
37
Reaction Quotient
Q= [C]^c x [D]^d/[A]^a x [B]^b
Using initial concentrations
38
Relationship between k and q
kq flow right
39
Hundred rule
if the initial concentration divided by k is greater than 100 than the x value can be discarded
Make sure you double check
40
Solubility equilibrium
solute(s) solute (aq)
solute cation (aq) + anion (aq)
ksp = [cation][anion]
41
ksp values
very soluble x>100g/L
Soluable 100>10 g/L
slightly soluable 10 > 1 g/L
Insoluble <1 g/L
The smaller the ksp the more it wants to precipitate
42
Robert boyle's acid and base
Acids taste sour, are corrosive, change vegetable dye colour from blue to red and can be neutralized by bases.
Bases taste bitter, feel slippery, change vegetable dyes colour from red to blue and can be neutralized by acids
43
Svante Arrhenius acid and base
Ion compounds disassociate in water to produce ions.
Acids are neutral compounds that ionize in water producing Hydronium
Bases are neutral compounds that ionize on aqueous solutions to produce hydroxide ions
Only applies to aqueous solutions, didn't explain whys some compounds with hydrogen are able to disassociate while others don't.
44
Bronsted and lowry acid and base
acids are proton donors
bases are proton acceptors
Proton comes from the hydrogen ion (hydronium)
45
Amphoteric
can both give and receive protons
46
Auto-Ionization of water
```
[H30]= 1x10&-7
[OH] = 1x10&-7
```
kw = 10^-14
kw= [H30]/[OH]
47
Strong acids
Give protons and don't take it back
48
weak acid
Give protons and sometimes take back
49
Strong Bases
Receives and never gives it back
50
weak base
Receives protons and sometimes gives it back
51
Strong acid examples
Hydrochloric acid HCl
Nitric acid HNO3
Sulfuric acid H2SO4
52
Strong Base examples
NaOH
Ca(OH]2
K(OH)
all ionic compounds that have hydroxide ions are strong bases.
53
Polyprotic acids
have more than one hydrogen atom. Donate them one at a time. Donte the first one "strongly" and the second one more weak
54
Titration
A titration is a technique where a solution of known concentration is used to determine the concentration of an unknown solution. Typically, the titrant (the know solution) is added from a buret to a known quantity of the analyte (the unknown solution) until the reaction is complete.
55
What pH will a Strong Acid and Base produce when neutralize?
7
56
What pH will a Weak Acid and Acid Base produce when neutralize?
9
57
What are electrons in quantum mechanics
waves that exist in very specific principle energy levels (n) due to their 3d standing waves.
They exist in 3d orbitals.
58
How many electrons are in each level
according to Boyle there are 2n^2 electrons in each energy level
59
What are the letters that represent the energy levels of orbitals
s-p-d-f
60
the max number of each orbital that can exist in every level
energy level. max orbital. max elec
s. 1 2
p. 3. 6
d. 5 10
f. 7 14
61
Aufbau Principle
When electrons fill the possible energy levels within an atom. They always fill the lowest energy levels first
62
Hunds Rule
Dani's parking rule
| electrons always want to sit by themselves. Hund's occupy separate orbitals rather than pair
63
Democritus
300 BC
Oposed the philosophical notion of infinitely divisible matter.
Matter consists of very small indivisible particles called 'atoms'
Believed that nothing comes from nothing and everything could be explained by the motion of particles.
Pupil of Leucippus of Miletus
64
JJ Thomson
1897
Cathode Ray tube gave evidence of negatively charge particles in atoms. Plum pudding model. Electrons are embedded in a positively charged solid sphere. The atom is still neutral
Cathode ray tube: A vacuum tube with a flourecent backing was hooked up to a battery so that electricity would flow through. a beam was produced and when a magnet was held close to the tube the beam would repel the negative side and attract the positive side. Therefore showing that there are negatively charged particles.
65
Ernest Rutherford
1911
Gold foil experiment
Tiny % of alpha particles deflected at large angles by thin gold foil.
Nuclear model of the atom. Most of the atom is empty space with a small positively charged nucleus. The nucleus accounts for almost all of the mass of the atom
Also discovered the proton. The smallest particle of positive charge is the proton which is located in the nucleus
66
James Chadwick
1932
Discovered the neutron using a mass spectrometer. found that atoms of the same element can have different masses. Isotopes are atoms of the same element with different number of neutrons.the nucleus contains protons and neutrons of approximately the same mass. Element is determined by the number of protons. Total number of neutrons and protons is the mass number. improved on the nuclear model by including 3 subatomic particles
67
Max Planck
1900
lack Boy Radiation Experiments. A heated object gives off electromagnetic radiation and can emit light (red-yellow-white). Heated atoms emit energy when they change from one energy value to a lower one in whole number multiples of a certain energy. Energy is no continuous but is given off in little bundles called quanta.
Planck's constant= 6.63x10^-34
E=nh x f
68
Albert Einstein
1905
Photoelectric Effect
Light shone on metal produces a release of electrons. The frequency (colour) of the light is the most important factor in producing this effect.
Waves can behave as particles. Each packet of energy is called a photon. An electron cannot break free form the atom unless a certain minimum quantity of energy is absorbed from a single photon
69
Niels Bohr
1913
Spectral line Experients. The spectra of elements is a series of specific lines. Therefore only photons with a certain quanta of energy can be absorbed or emitted by an atom. Therefore the energy of the electrons in the atom must also be quantized. Bohr model of the atom. Determined that electrons exist at a certain fixed distance from the nucleus with a fixed energy. Electrons can change their energy only by undergoing a transition from one stationary state to another which involves a fixed amount of energy. When this fixed amount of energy is released a specific wavelength of light is released
Stationary states (n) Principle quantum number
70
Albert Michelson
1891
discovered lines within the spectral lines bohr had discovered. Sommerfeld used elliptical electron orbits to explain it.
71
Arnold Sommerfeld
1915
| Based off of albert michelson's work determined the secondary quantum number. It reflects the orbital shape.
72
Peter Debye
1916
Third quantum number: the magnetic quantum number
The spectral lines could be further subdivided if the discharge tubes were placed near a strong magnet.
ml
73
Wolfgang Pauli
1925
Forth quantum number (ms).
Pauli explained whys one objects could experience weak magnetic attraction, due to their spinning electrons. Electron spins could ein one of two directions.
74
Louis DeBroglie
1924
Electron diffraction experiment. Electrons have a diffraction pattern similar to that of a wave when passed through a crystal.
Particles can behave as waves. Moving electrons may e considered as a wave as well as a particle.
Wavelength =placnk's content/mass x velocity
h=h/mv
75
Erwin Schrodinger
1926
Enivsioned electrons as stable circular standing waves around the nucleus. Developed a mathematical wave equation. An electron can only have certain energies because of the requirement for only whole numbers of wavelengths. This equation calculates the identity of the regions in space where there is a high probability of locating an electron with a specific energy at any given time.
76
Werner Heisenberg
1926
To measure any particle we have to touch it which changes its information.
Heisenberg's Uncertainty principle. Demonstrated mathematically that there are limits to our ability to know both where a particle is and its speed. Therefore we can only predict the probability of finding an electron in a certain location.
77
What are a few important unanswered questions
What does reality consist of?
| How does matter originate?
78
What are the two approaches to answering the unanswerable questions?
Idealism: Spirit or mind or the objects of the mind are primary and matter secondary, There is a truth the is beyond material, spirit is first
Materialism: Matter is primary and mind or spirit or ideas are secondary, the product of matter acting upon matter.
79
Atomos
greek prefix a and tomos
| meaning not cut
80
Socrates
asked lots of questions, make sure ou know thyself, never wrote anything down
81
Plato
wrote and provided answers through stories and questions. Thought smart people should be the kings of the world
82
Aristotle
wants to be king of the world Alexander the great was Aristotle's student. only gave answers. Stradles the canoes of idealism and materialism. Turn could be reached through rational analysis of the senses. Endorsed 4 elements of earth wind fire water.
Believed matter could be infinitely subdivided.
Matter had no specific origin.
83
Galileo Galilei
First great modern experimenters
84
Francis Bacon
published the ovum organum advancing experimentation to eliminate alternate theories began
85
Empirical reasoning
firm foundation on which truth could be reached from physical testing of theories.
86
Scientific method
```
ask a question
do background research
construct a hypothesis
test your hypothesis by experiment
analyze your data and draw a conclusion
report your results, were you right?
```
87
John Dalton
1766-1844
English school teacher
did research and experimenting with gases
disagreed with Aristotle
published the first atomic theory in 1805.
Billiard ball model
circle is perfect so atom is a sphere because god is perfect
88
what was the fancy smart people conference called?
International Solvay Conference.
| Special one was the 5th annual in October 1927
89
Principle quantum number
1913 by neils bohr
the maximum number of electrons per principle energy level 2n^2
Used spectra lines
90
Secondary Quantum number
Albert Michelson and Arnold Sommerfeld.
(l)
Examined spectral lines and found lines within the single line.
Used elliptical electron orbits to explain it
Orbital is a 3d cloud that electrons move around
l reflects the orbital shape
l = n-1
spdf
91
Third quantum number
Magnetic quantum number
found by placing the gas near a strong magnet. Produced spectral lines within the lines within the lines.
explained that suing different planes of orbital orientation
92
Fourth Quantum number
ms
the spin quantum number
Paramagnetism- a relatively weak attraction to a magnetic field
Wolgang Pauli.
Electrons spin and can spin clockwise or counter-clockwise. +1/2 or -1/2
93
Pauli Exclusion principle
two electrons with identical spin cannot occupy the same quantum state simultaneously
94
Schrodinger's cat paradox
illustrates the superposition of opposite wave function realities that can co-exist until observed
95
Electrons
1. no pretty circles
2. its a wave
3. we don't know everything
4. if we know something its just not completely
5. MATH
96
Classical vs Quantum
1. C: energy is continues
Q: energy increases in quanta
2. c: Light broken into continuous rainbow spectrum
Q: atoms emit light in very specific discreet spectral lines
3. C: waves are continuous oscillations
Q: Albert discovered light waves behave as discreet particles and thus introduced the concept of the photon
4. C: waves and particles are different
Q: electron is a wave with mass and charge
5. C: objects orbit in 2D circular or elliptical orbits
Q: 3d orbits
6. C: location of an object can be found with certainty.
Q: only known with probabilities
7. C: can know location and momentum of objects
Q: Impossible to know both the location and momentum
8. C: applies to regular objects that we can see.
Q: applies to objects less than 10^-9m in length.
