Chemistry 1 Flashcards
1
Q
Effect on equilibrium:
Changing TEMP if the rxn is EXOthermic
A
CHANGES Keq
shifts equilibrium
increase temp=
- shifts left
- Keq decreases
decrease temp=
shifts right
Keq increases
2
Q
PT trends: trend for most metallic/gives up VE easiest
A
to the left and down=most metallic & most willing to give up its ve
2
Q
- Define “Work Function”
A
- bombarding metals with (sufficient) energy
causes valence electrons to be ejected
2
Q
If you add MORE energy than Work Energy ( “ φ “), what happens?
A
- the energy is transferred
…into the KE of the ejected valence electron
3
Q
Periodic Table
- Where is the S-BLOCK?
A
the first 2 columns
4
Q
WORK FUNCTION
- Give the formula
A
KE=hf - φ
or KE=E - φ
(since E=hf)
5
Q
Think of NEUTRONS as:
A
PROTON + ELECTRON
5
Q
How do you calculate Percent (%) Mass?
A
Percent % Mass=
mass of ONE element / TOTAL mass of cpd
x 100%
6
Q
Think of METALS as:
A
LARGER atoms with LOOSELY held electrons
6
Q
What is “Theoretical Yield?”
A
amt of product (in g) that would be produced IF rxn ran to 100% completion
7
Q
Elements in the same FAMILY have…
A
similar CHEMICAL and PHYSICAL properties
7
Q
Finding the LIMITING REAGENT
- What 2 things MUST you do BEFORE you can go about finding the limiting reagent?
- Once these 2 things are done, what are the 2 steps to finding the limiting reagent?
A
You MUST:
- Have a balanced equation
- Convert to moles first
STEPS:
- Compare # of moles YOU have to # moles REQUIRED TO RUN THE REACTION
- as indicated by coefficients
- The reactant you run out of FIRST:
= the limiting reagent
8
Q
- Metals like to ____ e’s and form___
- Metals are (3 physical properties)
- What are metals’ conductive properties?
A
Metals like to LOSE ELECTRONS and form CATIONS
Metals are:
- lustrous
- ductile
- malleable
Metals are good conductors of heat AND electricity
8
Q
What qualifies something as a good “Electrolyte?”
A
-
Covalent cpds that dissociate 100% in water are GOOD electrolytes
- ex: SA’s & SB’s are good electrolytes
ALL IONIC compounds that are water soluble are GOOD electrolytes
9
Q
Recognizing Compounds:
Sulfate
A
SO42-
10
Q
Yield is a function of what 2 things?
Addition of what NEVER increases yield?
A
- Yield is a function of: R
- Reactants
- Equilibrium
NOT Rate!
- Adding a catalyst with increase rate, but not yield
11
Q
Define “Radioactive Decay”
A
the process by which UNSTABLE atoms change their chemical composition over time
12
Q
- Element symbols
- Z=
A
- Atomic NUMBER
- (number of protons)
13
Q
Will NaCl or KCl have a higher CONDOSITY?
Why?
A
KCl
because K is more METALLIC than Na
- therefore is a better conductor
13
Q
To get a MOLECULAR formula (NOT Empirical!) from Percent Mass:
- What do you need?
- How do you do it?
A
You need the MW of the unknown!
- Divide MW of unknown by MW of the empirical formula
- which should be a whole number
- Multiply each subscript by that #
- …to get the molecular formula
14
Q
What is the definition of “Atomic Weight?”
A
is the mass of 1 mol of any atom (g/mol)
15
Q
What are the 2 adjustements to Bohr Model?
A
- Electrons have dual nature–
- act as a wave AND a particle
- ex: light
- act as a wave AND a particle
- E’s DONT orbit in circular fashion
- i.e., s,p,d, & f have DISTINCT shapes
15
Q
Anti Bonding vs Bonding orbitals
- Which kind is HIGHER in energy?
A
ANTI bonding
16
Q
What does the “Pauli Exclusion Principle” state?”
A
- NO 2 e’s can have the exact same 4 quantum numbers
They CAN have UP TO 3 identical numbers
but they will have different spin states (4th quantum #)
16
Ammonium
NH4+
16
Ionic cpds have a hi/lo BP
High
17
When electron drops to a lower level, what happens?
energy is released as a photon (this is electromag. radiation)-energy released is exactly equal to diff b/t 2 energy levels
17
Q
rxn goes to right (favors products)
17
Ionic cpds are \_\_\_at room temp
solid
18
**Carbonate**
**CO32-**
19
Why does ATP being converted to ADP release energy?
because forming of new bonds in ADP releases more energy than was req'd to break bonds in ATP (energetically favorable)
19
Coordinate Covalent bonds: what do the donor and recipient molecules need to have?
donor: one LPrecipient: needs empty orbital
20
**CHLOR**_ITE_****
**ClO2-**
21
Isotope definition
different version of the same atom, with different # neutrons
22
Radioactive decay common in what kinds of questions? (2)
Conservation of momentumreverse collisions
22
**NITR**_ATE_****
**NO3-**
24
Per coulombs law, smaller atoms have what?
Greater Force
25
Work function formula. What can you substitute for "E?" (2 options)
KE=E-IPyou can use E=hf OR E=hc/lamda
25
**MANGAN**_ATE_****
**MnO42-**
25
Percent yield formula
actual yield/theoretical yield x 100%
27
Third quantum number, aka
aka "mt" or "magnetic quantu, number
28
Fourth quantum number gives what?
gives the spinis either + 1/2or -1/2
28
Empirical vs Molecular formula
Empirical: represents lowest possible # of moles of each element that can be present in a cpd, while still maintaining the same mole-to-mole ration b/t the elements Molecular: ACTUAL # of moles of each element found in a compoundbasically, empirical is when you reduce the molecular formula as far as you can go
29
Beta decay
neutron changed to proton with ejection of e'
31
Larger atoms are better at what? What are properties of orbitals of big atoms
at stabilizing chargesdont form pi bonds, and have d orbitals where they "store" extra electrons
31
Q\>K
rxn proceeds to left (favors reactants)
32
What should you remember about transition metals emitting light?
Trans metals have partially filled d orbitals-this allows e's to absorb at many different wavelengths--color emitted is due to the few wavelengths of UNabsorbed light being reflected
33
* Element symbol A=
* mass number (protons + neutrons)
34
At a rxn equilibrium...
forward & reverse cancel outdeltaS is at maximum possible valuedeltaG is at 0
35
Inorganic Nomenclature: Binary cpds
name element furthest down and to the left FIRSTuse poly prefixes (di, tri, tetra) if neededSome have common names, like ammonia and water
36
Ionic characterWhat 2 elements have highest IC?
-all bonds between 2 different elements have IC-is a measure of polarity between bondLiCl=highest IC
37
Hydroxide
OH-
38
PT: d block
transition metals
39
Define le chatelier's principle
systems already at equilibrium that experience a change will SHIFT, to reduce the effects of that change
40
**BICARBONATE**
**HCO3-**
41
If you add LESS energy than Work Energy (IP), what happens?
the ve' wont be ejected
41
Cyanide
CN-
42
Keq (equilibrium constant) can only be calculated when its at equilibrium. At any other non-equilibrium point, when you use the same calculations, what do you get instead?
reaction quotient, Q
44
Do all isotopes have odd mass #'s?
Not all (ex: carbon-14), but many DO
45
Fourth quantum number, aka
aka "ms" or "the electron spin quantum number"
47
How many "rooms" in each subshell? s,p,d,f
1,3,5,72,6,10,14 electrons in each subshell
48
Think of protons as:
neuron+positron
49
* What are the 4 Gen Chem **reaction types** we need to know?
1. Com**bin**ation
2. Decom**po**sition
3. **Single** displacement
4. **Double** displacement
* "metathesis" rxn
50
Bond length definition
distance b/t 2 nuclei of atoms forming a bond
51
Electron configuration definition
a list of quantum numbers and the # of e's in each
53
What does a LARGE Keq value mean?
at equilibrium, there are a lot more products than reactants
54
**HYPOCHLORATE**
**ClO-**
55
**CHLOR**_ATE_****
**ClO3-**
56
Inorganic Nomenclature: acids
"ate-ic""ite-ous"single ion: "ide-ic", add "hydro" as prefix
57
Why dont big atoms form pi bonds?
theres less overlap of P orbitals (much weaker)
58
Heisenberg uncertainty principle
the more we know about an e's position (x), the less we know about its momentum (p)
60
PT: Lathanides
upper row of f block
61
**NITR**_ITE_****
**NO2-**
62
Velocity of ejected ve' formula
V=F(lamda)
63
Zeffective definition
* As atoms increase in size, theyre surrounded by more electrons
* The "effective nuclear charge" felt by ve's DECREASES, because there are less e's in between nucleus and outer shell to "shield" the ve's
* H feels full Zeffective, because there are **no electrons in between**
64
Are cations larger or smaller than their neutral counterparts? Why?
Smallerbecause (+) charge "sucks in" electron cloud. Most cations form in order to match the configuration of the nearest noble gas, so they totally LOSE an entire shell!
65
Anti Bonding orbitals
contain "out of phase" electrons that are "repulsive" (Therefore, higher in energy)
66
Permanganate
MnO4-
67
third quantum number gives what?has a value of what?
gives orbital orientation--designates the orientation of subshell where electron is most likely to be found has a value of -l or l
68
Inorganic Nomenclature: transition metals
roman numerals show oxidation state of metal
69
First quantum number \*\*notable exception?
gives the shell represents relative energy of electrons in that shellexception: 3d has more energy than 4s
70
Effect on equilibrium: removing product
Right
71
Effect on equilibrium: removing reactant
Left
73
Energy levels are \_\_\_\_\_!
Quantized! energies can be in energy level A or B, but never in between
74
Periodic table: what is a "Period"
horizontal row
75
Coordinate covalent bond definition
covalent bond where both e's shared in the bond are donated by ONE atom ("donor")-usually multiple donor molecules surrounding a single recipient
76
Cation definition
any atom or molecule with FEWER e's than protons (positive charge)
77
How to balance gen chemical rxns (7 steps)
1) balance carbons2) balance hydrogens3) balance oxygens4) balance remaining elements5) use fractions if necessary: (if 7 O2's on one side and 2 on other, put 7/2 in front of O2 to balance)6) Multiply all species on both sides by the denominator of any fractions you might have7) Double check!! Count them up. Remember to multiply by coefficients
79
Anion definition
Any atom or molecule with MORE e's than protons (negative charge)
80
Gamma emission
gamma rays usually emitted as BYPRODUCTS of other kinds of decay\*Gamma decay doesnt change # of nucleons!
81
How to get a formula using % mass (1,2,3A-D)
1) change % mass for each element into grams (15%=15 g)2) convert grams to moles by dividing by molar mass3A) Look at element with lowest # moles3B) how many times will it divide into each of the other molar amts for each of the other elements? 3C) this # is subscript for each element in empirical formula3D) if subscripts are are lowest common denominator, reduce it
82
Effect on equilibrium: adding product
Left
83
How does disrupting equilibrium affect Keq (equilib const)?
It DOESNTIt move the equilibrium, but the Keq remains the same
85
Difference between ionization energy and work function
ionization energy measured for Ione atoms in a GASEOUS stateWork function refers to ve's being ejected from surface of a SOLID metal
87
Regarding BDE...more stable (ex: N2) =?
higher BDE
88
Ammonia
NH3
89
Second quantum number
aka "l" or "azimuthal quantum number" Gives subshell or orbitalhas values of 0,1,2,3
90
How to predict species that req's MOST oxygen needed for combustion
add 1.0 for each C subtract .5 for each OHigher resulting #=more O2 needed to combustex: C3H8=+3 (req's most O2 to combust)C3H8O=+2.5
91
Effect on equilibrium:
**Increase** pressure
eq. shifts to side with
**FEWER** moles of gas
93
MEtals are involved in what kinds of bonds with what?
Ionic bonds with nonmetals
94
When you see a question asking for an element/cpd "closest to" or "similar to" something, what will you think of?
Look at elements in the same family & same group
95
Bond Dissociation energy (BDE) definition
energy stored in a bond
97
Covalent vs Ionic bonds
covalent: b/t 2 nonmetals, involve sharing of e'sionic: b/t metal and nonmetal and are due to electrostatic attraction
98
Energy Levels represent:
energies of electrons in an atom
99
actual yield
amt of product (in g) you actually obtain at the end of your experiment
101
Half life definition
t 1/2 is half the time req'd for half of mass of that substance to disappear due to radioactive decay
102
Positron emission
proton changed to neutron with expulsion of a positron
103
Electron capture
proton changed to neutron via capture of e'
105
Think of non-metals as:
smaller atoms with tightly held e's
107
Nonmetals form ____ ionsHave higher/lower MPs than metals?Form what kinds of bonds with what?
Form negative ions (anions)have lower MP than metalsform covalent bonds with other nonmetals
108
2 ways to increase yield
1) Start with more reactants -increases overall quantity of yield, but not % yield-you need to add more of the LIMITING REAGENT...adding more of what isnt the LR has no effect2) Shift equilibrium to right, using Le Chatelier's principle-most common method: remove products as soon as they form
109
What happens to the quantum level if you dont expose e' to enough energy?
energy doesnt get absorbed, no jump in level
110
Condosity
concentation (molarity) of an NaCl solution that will conduct electricity EXACTLY as well as the solution in question
111
Inorganic Nomenclature: general ionic cpds
name cation first, then anionCaSO4= calcium sulfate
112
Second quantum numbers what do 0,1,2, and 3 represent?
0=s orbital1=p2=d3=f
114
Inorganic Nomenclature: monatomic ions
replace last syllable with "-ide"Cl-=chloride
115
How to find theoretical yield
find limiting reagent, do mol-to-mole conversion to get moles of product, and convert to grams
116
PT: actinides
lower row of f block
117
Effect on equilibrium: decrease pressure
Eq. shifts to side with more moles of gas
118
Law of Mass action formula
Keq=[products]^x/ [reactants]^y\*pure liquids and solids never included
119
PT: f block
Lathanides and actinides
121
PT: p-block
6 columns from B--\>F
122
Alpha decay
loss of one Helium nucleus (Atomic mass # of 4, at. number of 2)
123
Forming bonds _______ energyWhy? What example mixes lots of people up?
releases!!Atoms dont want to form bonds. Needs to go from higher to lower energy in order to happen, which releases energy.example of this: ATP--\>ADP
124
**PHOSPHATE**
**PO43-**
125
Bonding orbitals
contain electrons that are "in phase," and are said to be "attractive"
126
Effect on equilibrium: adding reactant
Right
127
**[A] versus t**
## Footnote
would be **linear** for a ____ order reaction
**ZEROTH ORDER RXN**
128
**ln [A] versus t**
## Footnote
would be **linear** for a ___ order reaction
**FIRST** ORDER RXN
129
**1 / [A] versus t**
## Footnote
would be **linear** for a ____ order reaction
**SECOND** ORDER RXN
130
_**ZEROth ORDER** Reactions_
What do they look like on plots of:
* [A] versus t
* ln [A] versus t
* 1 / [A] versus t
For which of these plots is a zeroth-order rxn **LINEAR?**
Linear on:
## Footnote
**[A] versus t**
131
_**FIRST ORDER** Reactions_
What do they look like on plots of:
* [A] versus t
* ln [A] versus t
* 1 / [A] versus t
For which of these plots is a first-order rxn **LINEAR**?
Linear on:
## Footnote
**ln [A] vs. time**
132
_**SECOND** **ORDER** Reactions_
What do they look like on plots of:
* [A] versus t
* ln [A] versus t
* 1 / [A] versus t
For which of these plots is a second-order rxn **LINEAR**?
Linear on:
## Footnote
**1 / [A] vs. time**
133
A chemist could **identify the order** of zinc in the rate law for the equation given below by performing which of the following procedures in the lab? (Note: Sulfuric acid is known to be a **first order** reactant)
***Zn(s) + H2SO4(aq) ⇒ ZnSO4(s) + H2(g)***
A) Graph the [Zn], ln[Zn] and 1/[Zn] versus time
* while holding the [H2SO4] **constant**
B) Graph the [Zn], ln[Zn] and 1/[Zn] versus time
* while **varying** the [H2SO4]
C) Graph the [Zn], ln[Zn] and 1/[Zn] versus time
* while holding the [H2SO4] **in excess**
D) The order of Zn is **already** known
* because solid reactants are **always** zero order and therefore **omitted** from the rate law
**C**
## Footnote
* To determine the order of Zn the chemist needs to **REMOVE** the effect of sulfuric acid (the other reactant) because we **know** it is first order and therefore affecting **rate**
* Putting it in **excess** makes it effectively **zero** order under those conditions
***_and any effect remaining must be due SOLELY to Zn_***
* This makes C the best answer
134
Looking on the Periodic Table, what represents:
* the **ATOMIC MASS**
* the **ATOMIC NUMBER**
*What do both of these **represent**, individually?*
135
Of the substances listed in Table 1 capable of combustion with O2, which would require the **greatest number of moles of oxygen** to run the combustion reaction to completion?
* A. Benzene
* B. Water
* C. Methane
* D. Acetone
**A**
## Footnote
_Remember_:
* **Most** gases and **ALL** hydrocarbons are combustible
* Water is **NEVER** combustible
After that, make a ranking system in which you assign a **+1 for each carbon** contained in a compound and a **-0.5 for each oxygen** in a compound
The compound with the **largest** tally will require the **most** O2 to combust
In this case it is easy because **BENZENE** has far more carbons than anything else
