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Flashcards in Chemistry 1 Deck (136):
1

Effect on equilibrium:

Changing TEMP if the rxn is EXOthermic

CHANGES Keq

shifts equilibrium

increase temp=

  • shifts left
  • Keq decreases

decrease temp=

shifts right

Keq increases

2

PT trends: trend for most metallic/gives up VE easiest

to the left and down=most metallic & most willing to give up its ve

2

  • Define "Work Function"

  • bombarding metals with (sufficient) energy

causes valence electrons to be ejected

2

If you add MORE energy than Work Energy ( " φ "), what happens?

  • the energy is transferred

...into the KE of the ejected valence electron

3

Periodic Table

  • Where is the S-BLOCK?

the first 2 columns

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4

WORK FUNCTION

  • Give the formula

KE=hf - φ

or KE=E - φ

(since E=hf)

5

Think of NEUTRONS as:

PROTON + ELECTRON

5

How do you calculate Percent (%) Mass?

Percent % Mass= 

mass of ONE element / TOTAL mass of cpd

x 100%

6

Think of METALS as: 

LARGER atoms with LOOSELY held electrons

6

What is "Theoretical Yield?"

amt of product (in g) that would be produced IF rxn ran to 100% completion

7

Elements in the same FAMILY have...

similar CHEMICAL and PHYSICAL properties

7

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? 

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You MUST:

  • Have a balanced equation
  • Convert to moles first

STEPS:

  1. Compare # of moles YOU have to # moles REQUIRED TO RUN THE REACTION
    • as indicated by coefficients
  2. The reactant you run out of FIRST:

​​= the limiting reagent

8

  • Metals like to ____ e's and form___
  • Metals are (3 physical properties)
  • What are metals' conductive properties?

Metals like to LOSE ELECTRONS and form CATIONS

Metals are:

  1. lustrous
  2. ductile
  3. malleable

Metals are good conductors of heat AND electricity

8

What qualifies something as a good "Electrolyte?"

  • 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

Recognizing Compounds:

Sulfate

SO42-

10

Yield is a function of what 2 things? 

Addition of what NEVER increases yield?

  • Yield is a function of: R
    • Reactants
    • Equilibrium

NOT Rate!

  • Adding a catalyst with increase rate, but not yield

11

Define "Radioactive Decay" 

the process by which UNSTABLE atoms change their chemical composition over time

12

  • Element symbols
    • Z=

  • Atomic NUMBER
    • (number of protons)

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13

Will NaCl or KCl have a higher CONDOSITY?

Why?

KCl

because K is more METALLIC than Na

  • therefore is a better conductor

13

To get a MOLECULAR  formula  (NOT Empirical!) from Percent Mass:

  • What do you need?
  • How do you do it?

You need the MW of the unknown!

  1. Divide MW of unknown by MW of the empirical formula
    • which should be a whole number
  2. Multiply each subscript by that #
    • ...to get the molecular formula

14

What is the definition of "Atomic Weight?"

is the mass of  1 mol of any atom (g/mol)

15

What are the 2 adjustements to Bohr Model? 

  1. Electrons have dual nature--
    • act as a wave AND a particle
      1. ex: light 
  2. E's DONT orbit in circular fashion
    • i.e., s,p,d, & f have DISTINCT shapes

15

Anti Bonding vs Bonding orbitals

  • Which kind is HIGHER in energy?

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ANTI bonding

16

What does the "Pauli Exclusion Principle" state?"

  • 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

CHLORITE

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

NITRATE

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

MANGANATE

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)

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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. Combination
  2. Decomposition
  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

CHLORATE

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

NITRITE

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

would be linear for a ____ order reaction
 

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ZEROTH ORDER RXN

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128

ln [A] versus t

would be linear for a ___  order reaction

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FIRST ORDER RXN

129

1 / [A] versus t

would be linear for a ____ order reaction

SECOND ORDER RXN

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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:

 [A] versus t 

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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:

ln [A] vs. time

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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:

1 / [A] vs. time

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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

  • 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? 

 

 

 

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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

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A

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