Chem-Phys Flashcards

Question

What is avogadro's number?

Answer 1

N_A= 6.02 x 10²³

Answer 2

h = 6.626 x 10^-34J x s

Answer 3

E = h*f* E = energy of quantum *f* = frequency h = Planck's constant

Answer 4

L = nh/2π L = angular momentum h= Planck's constant n= principal quantum number --\> subshell (s=1, p=2, d=3, f=4)

Answer 5

E = -R_H/n² E = energy of electron (J) R_H = Rydberg unit of energy = 2.18 x 10^-18J/electron n = principal quantum number

Answer 6

E = hc/λ E = energy of photon (J) h = Planck's constant (6.626 x 10-34 J x s) c = speed of light = 3 x 10⁸ λ = wavelength (nm)

Answer 7

E = -R_H[1/n₁²- 1/n_f²] E = Energy assocaited with jump J R_H = Rydberg unit of energy = 2.18 x 10-18 J/electron n = principal quantum number

Answer 8

**n** --\> the larger the integer value of n, the higher the energy level and radius of the electron's shell

Answer 9

The second quantum number is called the azimuthal (angular momentum) quantum number, and is designated by the letter ***l*** It represents the number of subshells within a given shell --\> related to **n** --\> for any value of ***n***, the range of possible values for ***l*** is ***0 to n-1*** ***l = 0 --\> s*** ***l = 1 --\> p*** ***l = 2 --\> d*** ***l = 3 --\> f***

Answer 10

max. # of electrons = 4*l* +2

Answer 11

The third quantum # is the magnetic quantum number (m_l) and it specifies the particular orbital within a subshell that an electron is most likely to be found --\> related to azimuthal quantum number --\> m_l= integers between -*l* and +*l*, including 0. The # of integers represents the number of orbitals (lines in e- configs.)

Answer 12

The 4th quantum # is the spin quantum # (m_s) --\> can be +1/2 and -1/2.

Answer 13

Hund's rule is that within each given subshell, the orbitals are filled such that there is a max. # of half-filled orbitals with parallel spins. Half-filled and fully-filled orbitals have lower energies (more stable) than other states. Example: Chromium's e- config. is [Ar]4s¹3d⁵instead of [Ar]4s²3d⁵

Answer 14

Paramagnetic

Answer 15

Diamagnetic

Answer 16

First... # values in data set (n) to determine Q₁ → n x 1/4 = x → (x)(x+1)/2 = Q₁ to determine Q3 → n x 3/4 = x → (x)(x+1)/2 = Q3 IQR= Q₃ - Q₁

Answer 17

If any values in 1.5 x IQR more or less than the mean then it is considered an outlier.

Answer 18

Take each data value, and subtract the mean from it and square the difference. After doing this for all of the values, take the sum of the results, and divide it by n-1, and take the sqaure root of that value.

Answer 19

You can use standard deviation to determine outliers by seeing whether or not the values fall within three standard deviations of the mean.

Answer 20

The the sum of their initial, individual probabilities, and from this subtract the probability that they will both occur. P(A or B) = P(A) + P(B) - P(A and B)

Answer 21

Begin w/ a desired cofidence level (usually 95%) → Find corressponding z or t score → multiply that value by the standard deviation and add and subtract from the mean in order to find the range of the true mean.

Answer 22

If the p-value is greater than our significance level, then that means that we fail to reject the null hypothesis, and vice versa.

Answer 23

Structural isomers (constitutional isomers) have the same molecular formulas.

Answer 24

Conformational isomers differ in a rotation around a single bond, and configurational isomers differ in molecular connectivity (differ with the breakage of bonds).

Answer 25

Enantiomers are non-superimposable mirror images (have the same chiral centers), while diastereomers are still chiral but are not mirror images of eachother because they differ at some (but not all) of their multiple chiral centers.

Answer 26

A meso compound is a molecule that contains a line of symmetry. These compounds are the molecular equivalent of a racemic mixture, and contain no optical activity.

Answer 27

[α] = α_obs/ c x l α_obs= observed rotation c = concentration in g/ml l = path length in dm 1 cm = 0.1 dm

Answer 28

1 kg • m / s²

Answer 29

1 kg • m² / s²

Answer 30

1 kg • m² / s³

Answer 31

1.6 x 10^-19J

Answer 32

Scalar: Dot product |A| x |B|cos θ

Answer 33

Vector: Cross product |A| x |B|sin θ

Answer 34

1. Start by pointing thumb in direction of vector 2. Extend your fingers in the direction of vector B 3. The direction your palm points is the direction of the resultant C

Answer 35

F_g = Gm₁m₂/ r² G = 6.67 x 10^-11 N • m²/ Kg²

Answer 36

G = 6.67 x 10-11 N • m2/ Kg2

Answer 37

1. A body at rest or in motion will remain that way, unless a net force acts upon it 2. An object of mass m, will accelerate when a vector sum of the forces results in some nonzero force vector 3. For every action, there is always an equal but opposite reaction

Answer 38

v = v₀ + at x = v₀t + at²/2 v² = v₀² + 2ax x = vt

Answer 39

F_g(parallel) = mgsinθ F_{g(perpendicular)} = mgcosθ

Answer 40

F_c = mv²/r

Answer 41

Group A elements contain valence electrons in s & p orbitals.

Answer 42

Poor conductors of heat and electricity.

Answer 43

Good conductivity but brittle.

Answer 44

Ionic radii of anions are larger than the atomic radius of that element, and ionic radii of cations is smaller than the atomic radius.

Answer 45

Ionization energy (energy required to remove an electron) increases from L → R and decreases from top → bottom.

Answer 46

Electron affinity increases from L → R, and decreases from top → bottom.

Answer 47

Electronegativity increases from L → R, and decreases from top → bottom, first 3 noble gases have no electronegativity.

Answer 48

Atomic radius decreases from L → R, and increases from top → bottom.

Answer 49

Second ionization energy will always be higher than first ionization energy.

Answer 50

sp → 50% s character sp² → 33% s character sp³ → 25% s character

Answer 51

1. He 2. Li 3. Be 4. B

Answer 52

1. P 2. S 3. Cl

Answer 53

1. High melting and boiling points 2. Solubility of ions in water 3. Good conductors of heat & electricity 4. Crystal lattice arrangement 5. Large electronegativity differences between ions

Answer 54

1. Hydrogen bonding 2. Dipole-dipole interactions 3. London dispersion forces

Answer 55

1/2mv²→ J (kg • m²/s²)

Answer 56

PE = mgh (J)

Answer 57

U = 1/2kx² k= spring constant x= displacement from EQ

Answer 58

E = U + K U = potential energy K = kinetic energy

Answer 59

If the net change in energy is 0 regardless of the path taken to get back to the initial position, then the forces are conservative. ΔE = ΔU + ΔK = 0

Answer 60

W_{nonconservative}= ΔE = ΔU + ΔK

Answer 61

1. Area under the curve on a P vs. V graph → P∆V 2. W = Fdcosθ 3. W = ∆K K → kinetic energy d → magnitude of the displacement θ → angle between the applied force vector and the displacement vector

Answer 62

An isobaric process is where pressure is constant, and the work can be calculated as PΔV.

Answer 63

An isochoric process is one where the volume is constant. There is no work done.

Answer 64

Power is the rate at which energy is transferred from one system to another and it is calculated with the equation P = W/t = ΔE/t.

Answer 65

Mechanical advantage is the ratio of magnitudes of the force exerted on an object by a simple machine, to the force actually applied on the simple machine. Mechanical Advantage = F_out/F_in

Answer 66

Decreases.

Answer 67

Increases.

Answer 68

Efficiency = W_out/W_in = (load)(load distance)/(effort)(effort distance)

Answer 69

Formal charge = #VE - #NBE - #BE/2

Answer 70

The Zeroth law of thermodynamics conveys the transitive property in thermal equilibrium. When the first object is in thermal equilibrium with the second object, and the second object is in thermal equilibrium with the third object, then the first object is said to be in thermal equilibrium with the third object.

Answer 71

F = 9/5C + 32 K = C + 273

Answer 72

Thermal expansion is when a change in temperature of most solids results in a change in their length. The equation for this: ∆L = αL∆T ∆L= change in length α= coefficient of linear expansion L = original length ∆T = change in temperature

Answer 73

Volumetric thermal expansion is the property of liquids to also expand as a result of a change in temperature. The equation for this is: ∆V= βV∆T ∆V= Change in volume β= Coefficient of linear expansion V= Original volume ∆T= Change in temperature

Answer 74

The coefficient of volumetric expansion is equal to three times the coefficient of linear expansion. β = 3α

Answer 75

The change in the total energy of a system is equal to the amount of energy transformed in the form of heat to the system, minus the amount of energy transferred from the system in the form of work. ∆U = Q - W ∆U = Change in the system's internal energy Q = Energy transferred into the system as heat W = Work done by the system

Answer 76

The change in internal energy is positive when temperature is increasing, and the change in internal energy is negative when temperature is decreasing.

Answer 77

Heat is a positive value when heat flows into the system, and heat is a negative value when heat flows out of the system.

Answer 78

Work is a positive value when work is done by the system, and it is a negative value when work is done on the system.

Answer 79

1 Cal = 10³ cal = 4184 J

Answer 80

1 calorie (little c) is the amount of heat required to raise 1 g of water one degree Celcius.

Answer 81

1. Conduction: Direct transfer of energy from molecule to molecule through molecular collisions 2. Convection: Transfer of heat by the physical motion of a fluid over a material 3. Radiation: Transfer of energy by electromagnetic waves

Answer 82

The specific heat of a substance is defined as the amount of heat energy required to raise one gram of a substance by one degree Celcius or one unit Kelvin (specific heat of water is 1 cal/g•K).

Answer 83

q = mc∆T q= heat gained or lost m = mass c = specific heat ∆T= change in temperature

Answer 84

q = mL q = amount of heat gained or lost from the material m = mass of the substance L = heat of transformation or the latent heat of the substance

Answer 85

An isothermal process is one where there is a constant temperature, and therefore no change in internal energy. Q = W

Answer 86

An adiabatic process is one where there is no heat exhange. Q = 0 ∆U = -W

Answer 87

An isochoric process is one where there is no change in volume, and therefore no work accomplished. W = 0 ∆U = Q

Answer 88

Entropy is a measure of the spontaneous dispersal of energy at a specific temperature. The equation is: ∆S = Q_rev/T ∆S = change in entropy Q_rev= heat gained or lost in a reversible process T = Temperature in Kelvin units: J/mol • K

Answer 89

The entropy of a system and its surroundings will never decrease, it will either remain zero or increase. ∆S_universe = ∆S_system + ∆S_surroundings\> 0

Answer 90

1 °C = 1.8 °F

Answer 91

A = 6.022 x 10²³ mol^-1

Answer 92

Molarity = Normality/ n

Answer 93

1. First determine the number of moles of each element in the compound by assuming a 100 g sample 2. Convert grams to moles 3. Simplest whole number ratio of the elements by either multiplying or dividing by an integer 4. To find the molecular formula divide the molar mass of the compound from the molar mass of the empirical formula to find an integer to multiple all of the atoms by

Answer 94

A combination reaction is when two or more reactants form one product. Example: 2 H₂ (*g*) + O₂ (*g*) → 2 H₂O (*g*)

Answer 95

A decomposition reaction is one where a single reactant breaks down into two or more products usually as a result of heating, high-frequency radiation, or electrolysis. Example: 2HgO (s) → 2 Hg (l) + O2 (g) Reaction Conditions: Heat (Δ)

Answer 96

A combustion reaction is a special type of reaction that involves a fuel (usually a hydrocarbon and an oxidant ⇒ normally oxygen). In most forms, the products are, carbon dioxide and water. Example: CH₄ + 2O₂ → CO₂ + 2 H₂O

Answer 97

A single displacement reaction is one where an atom or ion in a compound is replaced by an atom or ion of another element. Example: Cu (*s*) + AgNO₃ (*aq*) → Ag (*s*) + CuNO₃ (*aq*)

Answer 98

A double displacement reaction (metathesis) is one in which elements from two different compounds swap places with eachother to form two new compounds. Example: CaCl₂ (*aq*) + 2 AgNO₃ (*aq*) → Ca(NO₃)₂ (*aq*) + 2 AgCl (*s*)

Answer 99

A neutralization reaction is a type of double-displacement reaction where an acid and a base react in order to produce a salt, and usually water. Example: HCl (*aq*) + NaOH (*aq*) → NaCl (*aq*) + H₂O (*l*)

Answer 100

The limiting reagent is determined through comparing the moles of each of the reactants, with the stoichiometric ratios in order to find which reactant will get consumed first.

Answer 101

Percent Yield = (Actual Yield/ Theoretical Yield) x 100%

Answer 102

More acidic molecules will have smaller/more negative pKas. pKa = -log K_a

Answer 103

1. Charge: Nucleophilicity increases with increasing electron density (more negative charge) 2. Electronegativity: Nucleophilicity decreases as electronegativity increases because these atoms are less likely to share electron density 3. Steric Hindrance: Bulkier molecules are less nucleophilic 4. Solvent: Protic solvents can hinder nucleophilicity by protonating the nucleophile or through hydrogen bonding

Answer 104

1. Contain a positive charge or a positively polarized atoms that accepts an electron pair when forming new bonds with a nucleophile 2. Type of leaving group on electrophile, better leaving group allows room for the nucleophile to attack

Answer 105

1. The best leaving groups are able to stabilize extra electrons 2. Weak bases are good leaving groups because they have an extra set of electrons 3. The conjugate bases of strong acids tend to make good leaving groups 4. Leaving group abilitiy can be augmented by resonance and by inductive effects from EWGs → These help delocalize and stabilize negative charge 5. Alkanes and hydrogen ions will never serve as leaving groups

Answer 106

Unimolecular nucleophilic substitution reactions contain 2 steps. The first step is the RDS where the leaving group leaves, forming a carbocation. The nucleophile then attacks the carbocation, resulting in a substitution product. 3° \> 2° \> 1° carbocation stability, the most stable carbocation is preferred The products of the reaction will be a racemic mixture, because the incoming nucleophile can attack the carbocation from either side.

Answer 107

An S_N2 reaction (bimolecular nucleophilic substitution) contain only one step (concerted). The nucleophile actively displaces the leaving group in a backside attack. In order for this to occur, the nucleophile must be strong and the substrate cannot be sterically hindered. 3° \< 2° \< 1° carbon, because the less sterically hindered carbon is preferred The product of this reaction is stereospecific

Answer 108

Secondary alcohols can be oxidized to ketones.

Answer 109

Primary alcohols can be oxidized to either aldehydes or carboxylic acids, depending on the strength of the oxidizing agent.

Answer 110

anhydrides \> carboxylic acids and esters \> amides

Answer 111

ρ = *m* / V units: kg/m³ or g/cm³

Answer 112

1 g/cm³ or 1000 kg/m³

Answer 113

F_g = ρVg F_g= weight ρ = density V = volume g = acceleration due to gravity

Answer 114

The specific gravity of an object is often compared to that of pure water at 1 atm and 4°C. It is calculated using: SG = ρ / 1 g/cm³

Answer 115

Pressure is the ratio of the force per unit area. It is calculated using: P = F/A The units of pressure are pascals, which is equal to newton per square meter (1 Pa = 1 N/m²).

Answer 116

1.013 x 10⁵ Pa = 760 mmHg = 760 torr = 1 atm

Answer 117

Absolute or hydrostatic pressure is the total pressure that is exerted on an object that is submerged. P = P₀ + ρgz P = absolute pressure P₀ = incident or ambient pressure (pressure at the surface) ρ = density of the fluit g = acceleration due to gravity z = depth of the object

Answer 118

Gauge pressure is the difference between the absolute pressure inside the tire and the atmospheric pressure outside the tire. P_gauge = P - P_atm = (P₀ + ρgz) - P_atm when P₀ = P_atm equation is: P_gauge = P - P₀ = ρgz

Answer 119

Pascal's principle states that for fluids that are incompressible (fluids w/ volumes that cannot be reduced by any significant degree through application of pressure) a change in pressure will be transmitted indiminished to every portion of the fluid and to the walls of the containing vessel.

Answer 120

P = F₁/A₁= F₂/A₂

Answer 121

Archimedes' Principle suggests that a body wholly or partially immersed in fluid will be buoyed upwards by a force equal to the weight of the fluid it displaces. F_buoy = ρ_fluidV_{fluid displaced}g = ρ_fluidV_submergedg F_buoy = Magnitude of the buoyant force

Answer 122

An object will float if its average densitiy is less than the average density of the fluid it is immersed in. It will sink if its average density is greater than that of the fluid.

Answer 123

The percent directly indicates how much of the object is submerged.

Answer 124

Cohesion is the attractive force that a molecule of liquid feels toward other molecules of the same liquid, while adhesion is the attractive force that a molecule of the liquid feels toward the molecules of some other substance.

Answer 125

Viscosity is the resistance of a fluid to flow and is represented by the variable η. The SI unit for viscosity is the pascal-second. Pascal --\> unit of pressure --\> force per unit area --\> N/m² --\> viscosity --\> N x s / m²

Answer 126

Q = πr⁴ΔP/8ηL Q = Flow rate (volume flowing/time) r = radius of the tube --\> small change in radius has a significant effect on the pressure gradient ΔP = pressure gradient η = viscosity of the fluid L = length of the pipe

Answer 127

Turbulance is rough and disorderly flow.

Answer 128

Critical speed is the speed at which if exceeded can result in turbulant flow. It can be calculated through: v_c = N_Rη/ρD v_c = Critical speed N_R = Reynold's constant → Dependent on size, shape, and surface roughness of any objects within the fluid η = viscosity of the fluid D = diameter

Answer 129

The continuity equation is: Q = v₁A₁ = v₂A₂ This equation tells us that the volumetric rate of flow must be constant throughout a closed system.

Answer 130

P₁ + 1/2ρv₁² + ρgh₁ = P2 + 1/2ρv₂² + ρgh2 Statement of the conservation of energy within a closed fluid system. The sum of static pressure (P + ρgh) and dynamic pressure (1/2ρv²) will be constant within a closed container for an incompressible fluid not experiencing viscous drag.

Answer 131

Pitot tubes are used to determine the speed of fluid flow by determining the difference between static and dynamic pressure of the fluid at any given point along the tube.

Answer 132

If alcohol is the highest priority: -e ending is replaced by -ol, an alternative naming process is naming the alkyl group followed by "alcohol". When the alcohol is not the highest priority use the prefix hydroxy-.

Answer 133

Alcohols are capabile of intermolecular hydrogen bonding, resulting in significantly higher melting and boiling points. More hydroxyls = higher.

Answer 134

Electron-withdrawing groups increase acidity because charges like to be spread out as much as possible. Electron donating groups (alkyl) decrease acidity.

Answer 135

Primary alcohols can be oxidized to an aldehyde, but only by PCC. A stronger oxidizing agent (such as, Na₂Cr₂O₇ and K₂Cr₂O₇or CrO3) can turn primary alcohols into carboxylic acids.

Answer 136

Secondary alcohols can be oxidized into ketones, by using PCC or any other stronger oxidizing agent.

Answer 137

Tertiary alcohols cannot be oxidized because they are already as oxidized as they can be without breaking a carbon-carbon bond.

Answer 138

Alcohols can be protonated (H₂O) or reacted to form much better leaving groups called mesylates and tosylates. A mesylate is a compound containing the functional group -SO₃CH₃. A tosylate contains the functional group -SO₃C₆H₄CH₃. These groups can also serve as protecting groups.

Answer 139

Aldehydes or ketones can be reacted with two equivalents of an alcohol (diol), forming acetals (primary carbons with two -OR groups and a hydrogen atom) or ketals (secondary carbons with two -OR groups). These groups won't react with strong reducing agents such as LiAlH₄. The protecting groups can be removed with the addition of a strong acid.

Answer 140

Hydroxyquinones are the product of further oxidation of quinones (additions of one or more hydroxyl groups).

Answer 141

Ubiquinone is a biologically active quinone. It is also called coenzyme Q and is a vital electron carrier associated w/ complexes I, II, and III of the ETC. The long alkyl chain in this molecule allows it to be lipid soluable and act as an electron carrier within the phospholipid bilayer.

Answer 142

Jones oxidation requires CrO₃, H₂SO₄, and acetone.

Answer 143

Homotropic regulation is when a molecule serves as a substrate for a target molecule, as well as a regulatory molecule of the enzyme's activity. Oxygen participates in homotropic regulation with hemoglobin, due to cooperative binding.