TBR General Chemistry *I*

(+) & (-) Oxidation potentials

(+): more favorably oxidized than hydrogen gas. (-) potential: oxidation is LESS favorable than hydrogen gas.

Precious metals do NOT easily oxidize. Their cations have HIGH reduction potentials (more positive).

(-) reducing potentials → wants to lose electrons (+) reducing potentials → wants to GAIN electrons

A solid floating in a liquid

*% submerged = solid* density/*liquid* density.

*-* G: favorable redox rxn.

*+* emf: favorable redox rxn.

CaCl2 dissociates to what?

*1* Ca++ 2 Cl-

e- flow from *anode* to *cathode*

*Anions* flow *opposite* to e-flow.

1. Precipitation reactions (metathesis, double-displacement)

*Aqueous salt* (Na2CrO2) *+ Aqueous salt* (Sr(NO3)2) *=* *Soluble ions* (2NaNO3) + *Precipitate* (SrCrO4) Can be recognized by *a solid salt on the product side* of the equation.

*An*ions travel to the *an*ode

*Ca*tions travel to the *CA*THODE

In redox reactions

*Compounds*: oxidize or reduce. Agents are always reactants. *Atoms*: get oxidized or reduced.

Concentration vs. Mean Free Path

*Concentration* ↑ → mean free path *↓*

Medical imaging

*Diffraction of X-ray* X-rays can also undergo: 1. Refraction 2. Reflection They cannot undergo rebounding. This is associated with particles that rebound off surfaces they cannot penetrate.

*Is your equation balanced??*

*Do more limiting reagent questions*

Is *gas expansion* endothermic or exothermic?

*Endothermic*, because intermolecular *forces are weakened* as molecules move further away to fill the space.

Mass spectroscopy Measures *charge to mass ratio* for a charged particle. Used to determine *isotopes abundance.*

*F*orce depends on *mass* (so when equal force is applied to different masses, they accelerate at different rates). The radius of the particle's pathway (due deflection because of the magnetic field) is determined by the strike point against a collection detector. The mass to charge ratio is calculated by the radius of the arc.

Gas pressure

*F/A*rea exerted by gas thru collisions against container walls. As they frequently collide, P increases. atm unit.

Dilution terms

*Folds*: based on *total volume*. *Parts*: based on *volume added*. 3-fold dilution means: adding enough solvent to increase the volume 3 times its original amount. 2-part dilution: 2 parts solvent added to one part of the original solution.

*Heavier* particles have *LOWER velocity*, but collide with *GREATER force *(momentum).

*Light gas* molecules have *greater average speeds* and *greater collision frequencies*, but *(less momentum/ less collision force)*. Gas particles of *different masses* exert the *same pressure*.

Electron Affinity (EA)

*Negative EA* = energy is released *(favorable)*

*Electrons flow in redox* Reducing agents (gets oxidized, loses e-) → oxidizing agent

*Oxidation state* increases due to electrons loss (*electron poverty*). Ox state decreases due to electrons gain (reduction).

*Chalcogens (VI group)* Metalloids & nonmetals. Form *covalent* molecules *with nonmetals*.

*Oxidizing agents* (as neutral atoms) by gaining electrons 2 and *become -2 anions*. *Reactivity decreases* as they go down. Oxygen is *di*atomic (*O2*). Sulfur & selenium are *octa*tomic (*S8 & Se8*) Tellurium & polonium vary.

Gas *MACRO*scopic measurements (*PV=nRT*)

*P*ressure *V*olume Moles (*n*) *T*emperature

Gas equation

*R = 0.0821* L.atm.mole^-1.K^-1

Rutherford experiment

*Solids* are made of atoms with a *dense nucleus* and vast *empty space* between nuclei.

BP definitions

*T*emperature at which *vapor P*ressure *= atm*ospheric pressure. The temperature *above which* a substance may *NOT exist as a liquid.*

*Phases & Phase Changes*

*TBR Ch. VI*

*Stoichiometry*

*TBR Chemistry Chapter I*

Low IE = negative reducing potentials

..

*Chapter 2 starts here*

05/29/2018 Needs a quick pass. You already know most the info. If in a time crunch → do starred.

Solubility Rules (ID double-placement rxns)

1. *Group I cations* & *NH4+ salts* are water-*soluble.* 2. Nitrate (*NO3-*) salts are water *soluble*. 3. Sulfate ions (*SO4^2-*) salts are water *soluble* (*except for Ba++, Pb++, Hg++, Ca++)* 4. *Halide anions* salts are water *soluble* *except heavy metals like Ag+ and Pb+).* 5. Most *OH- salts are only slightly* water soluble. 6. *KOH & NaOH are substantially* soluble. 7. *Ca, Sr, Ba* hydroxide *anions (OH)* are *fairly soluble* in water. 8. Carbonate anion (*CO3^2-*), chromate anion (*CrO4^2-*), phosphate anion (*PO4^3-*) and sulfide anion (*S^2-*) salts are *only slightly soluble* in water.

Graph of vapor pressure of compounds A & B

1. As the mole fraction of a compound in solution decreases, its P vapor in solution decreases proportionally. 2. As the mole fraction of A is reduced, mole fraction of B is increased.

(CoCl4)^2- IUPAC name

1. Co has a +2 charge, so it is Co (II) Ligand number (Cl) is 4, that's tetrachloride. Co(II) tetrachloride

What is the mass percent of 1.0 m NaCl (aq) solution?

1. Convert 1 mole to grams: 58.5 grams. 2. Divide that mass (solute) by solution (solute + water) x 100%: 58.5/1058.5= 5.53%

The limiting reagent The lowest ratio of actual moles to needed moles. The reaction stops once it is consumed (regardless the amount of other reactants)

1. Determine the amount of all reactants & the mole ratio of the reactants. 2. If the ratio of the actual moles of A to B is greater than needed ratio of A to B from the balanced equation, then B is the limiting reagent. If the actual ratio of moles of A to B is less than needed ratio of A to B from the balanced equation, then A is the limiting reagent.

Electrochemical cells types

1. Galvanic (E>0) 2. Electrolytic (E<0)

Galvanic cell with the *greatest voltage* (most positive)

1. Greatest standard voltage E° 2. *Highest [cathode cation]* to [anode cation] ratio.

Mass spectroscopy function

1. It *ionizes* an element or compound to *generate a cation.* 2. *Accelerate* the cation in a *linear fashion* to enter a chamber *perpendicular to a magnetic* field. 3. Magnetic *force deflects the cationic* particle so it travels in a circular path. 4. The *mass to charge ratio* is determined from the radius of the semi-circular path. The mass to charge ratio of *EVERY isotope* can be determined.

Ideal gases

1. NO intermolecular forces. 2. Occupies no microscopic volume. 3. All collisions are *perfectly elastic*

Question: Which of the following forms of sulfur is considered the *strongest reducing agent*? H2SO4 Na2SO4 H2SO3 Na2S

1. Strongest reducing agent = lowest oxidation state (aka can get oxidized further). A, B are +6 (too large oxidizing number), no. Na2S = -2 (fully reduced), so it can get oxidized most. This makes it the strongest reducing agent.

Which solution has the GREATEST cation concentration?

1. The solution with a SMALLER MW yields more moles per gram (n= g/mw). 2. The solution with a higher ratio of cations to anions (NaCl) has a higher [cation] than one with more anions than cations (i.e. MgCl2)

Standard Temperature and pressure

22.4 Liters 1 atm 0 C

Kinetic Molecular Theory of Gases 1. Particles are *so small* compared to the *intermolecular distance* between them (*particles have zero volume*). 2. Particles *move in straight lines*. Direction changes only by its collision with another or wall. *Elastic collisions* and momentum is *conserved*.

3. Particles are in *constant random translational motion*. Gas pressure occurs by collisions *between particles and wall.* 4. They exhibit NO intermolecular forces. *Particles neither attract nor repel one another.*

Nickel di-cation electronic configuration

3d (l=2) orbital has the following *ml* values: *-2, -1, 0, 1, 2* The last electron is found in the 0 ml (count its 6 d-block electrons and you'll find out how)

Infusion Gas in

A gas passing from *OUT*side *to IN*side a container *through a pore* in the barrier.

Effusion Gas out

A gas passing from *inside to outside* a container through a *pore* in the barrier.

Electrode in photoelectric effect (absorbts lights → ejects e-) *KE = hf - work function* freq ↑, KE ↑

A larger/darker electrode → absorb more energy → eject more electrons. Ridged surface → lose more electrons (more surface area than flat) to absorb photons & eject more electrons.

If you want to measure the condensed vapor of a liquid, what kind of liquid do you mix it with before boiling?

A liquid with a HIGH BP and HIGH MW, so as the desired liquid evaporates and condenses, the testing liquid is still stable and not evaporated. A higher MW gives a smaller chance for error.

Electrochemical cell *electrode characteristics*

Able to transfer electrons without being involved in the reaction (*inert* chemically). High melting point. Minimal electrical resistance. Must be able to conduct electricity (not an insulator)

2M (s) + H2O (g) = 2MOH (aq) + H2 (g)

Acids naming: 1) Anion ending (-ide) → Hydro.....ic acid 2) Oxygenated: More Os → -ic Less Os → -ous

Acid-base rxns (neutralization)

Acids to recognize: HCl, H*NO3*, H2*SO4*, NH4+ Bases to recognize: NaOH, KOH, LiOH, *CaCO3* *Acid + base = Salt + water*.

Boiling point elevation ↑ with ↑ impurities (decreased surface area & increased intermolecular forces). *k water: 0.51* *ΔT = kim*

Adding *salt to water* creates *Ion-Dipole* interactions between Na+ & O in H2O which is *stronger than O---H* weaker interaction between water molecule (*H-bonding*) kb: solvent constant. (i: Van't Hoff factor) m: *molality*

Dilution

Adding a solvent to a solution, it increases the solution volume and decreases [solute] in solution. See *Molarity vs. Volume below* *M initial . V initial = M final . V final*

Anions are larger than neutral atoms. Within a period: Anions > cations

Adding electrons = enhanced repulsion

Breaking bonds is associated with phase change. Heating a liquid below its MP would only increase translational & vibrational KE. At its MP, energy is used for breaking bonds only, T doesn't change.

Adding salt to a form a solution: BP up, MP down

Colligative properties depend on number of particles

Adding solute to pure liquid: MP down, BP up (solute molecules occupy surface area and lower vapor pressure).

Metals can never be anions and halogens can never be cations, regardless the strength of the added voltage.

Adding voltage to water can yield H2 & O2 by water electrolysis

Question Review this again

Al (s) to AlO2- + 3e- MnO4- + 5e- = MnO (oxidation number calculation: -8 + Mn = -1, Mn = +7). In MnO, Mn is -2, so from 7 to -2 is 5e- transfer.

Salt bridge

Allows ions flow. They contain an aqueous solution held by a membrane that allows ions to diffuse from one half to the other.

Graham's law equation

Also, the equation is true for temperatures. *V2/v1 = √T2/T1* (opposite to the MM equation)

What is high electron affinity associated with? (think)

An element wanting to gain an electron (i.e. halogens)

Water phase diagram

An isothermal increase in pressure compresses ice into liquid water. *Negative slope* of liquid-solid.

In biochemistry (electrophoresis)

Anions go to (+) anode. *Ca*tions (& *e-*) go to the (-) *Ca*thode.

Covalent bond Relatively equal electrons sharing. 1.0 electronegativity

Anions naming: 1) Monoatomic, polyatomic → -ide 2) If it has multiple Os: a) more oxygens → -ate b) less oxygens → -ite

e-: to CAthode

Anions to ANode.

In physics

Anode (-) Cathode (+)

Anode & cathode metals At the cathode, positive charge ↓ due to reduction. Anions → cathode to anode (where positive charge increases due to oxidaiton)

Anode: metal needs to *lose* electrons *easily* (*low ionization energy*). Cathode: metal *loves e-*. Reduction is most favorable when the cathode metal has a *high oxidation state* (strong desire to gain e-).

What does it mean that *argon is denser* than air?

Argon *medium* would be *MORE massive* than air medium. *Weight* of argon would be *greater* than air weight. *Greater buoyant force upward* in argon medium. Remember weight is different, but mass is the SAME.

Boltzmann's Distribution

As *T increases*, each particle gains KE & distribution *Shifts to right*

*The most CO2 results from the compound with the GREATEST % mass of carbon*

As long as there are equal initial masses of all the choices (same starting grams)

Bigness coefficient (b)

Associated with the largest gas molecule.

Atom has more electrons that it normally has (-) charge CN- (since C here has 5 valence electrons instead of its max of 4)

Atom has less electrons than its normal (+) NH4+ (since N has 5 valence electrons)

a

Attraction coefficient. a is negative if particles repel (i.e. ionized particles)

*Mean free path [ ] *

Average *distance a particle travels before colliding* with another. This distance is the *same for the same concentration.*

At the mountains

BP is lower than normal (lower atm pressure)

As BP increases, its ability to vaporize decreases

BP ↑, P vapor ↓

Why is Li+ metal better as a reducing agent than Ca++?

Because alkali metals are more easily oxidized than alkaline earth metals.

Why do some material appear *black* in the presence of white light?

Because it absorbs all visible light that strikes its surface.

Liquid heat capacity is greater than all phases.

Because liquids can absorb *intermolecular vibration & translational KE*.

Why is *graphite* a good *conductor* in batteries?

Because of its *conjugation*. Graphite conducts electricity thru its π-network. Graphite is inert (good as a non-reactant electrode)

Metals have a LOWER ionization energy than nonmetals

Because their electrons can be ionized easily (photoelectric effect)

The first ionization energy for alkali metals is LOWER than it for alkaline earth metals

Because they can readily lose 1 electron to gain noble stability.

Supercritical fluid

Beyond critical point. Part fluid part gas (*amorphous*). It is impossible to distinguish between a fluid and a gas beyond the critical point.

Through electric fields, ANions migrate to the ANode

CAtions migrate to the CAthode

Oxidation of a hydrocarbon yields?

CO2 & water

Carbonic acid & carbonate

Carbonic acid H*2CO3* Carbonate: *CO3^2*-

Instability of the one electron in the p-orbital

Causes a sudden increase in electron affinity from Be to B, Mg to Al & Ca to Ga

Ammonia hydrogen bonding

Causes it to have a high BP, low vapor p.

In redox rxns, energy is proportional to?

Cell voltage Number of e-

*Which species can MOST readily remove an electron from a metal? 1. Cl2 2. Br2 3. CH2Cl2 4. CH2Br2

Chlorine is *more electronegative* (higher electron affinity) than bromine, eliminate 2 & 4. Chlorine in *Cl2 is MORE electron poor* than in CH2Cl2, so 1 is the right answer.

Pressure vs. collision force and frequency

Collision (frequency & force) ↑, P ↑

Gas MICROscopic measurements

Collisions frequency & collisions force. Mean free path. Molecules. Average KE

Real gases law The *b-value* for a gas describes its *size*. The a-value for a gas correlates with attractive intermolecular forces. When *polarity increases*, intermolecular forces increase and a-value increases)

Consider if the molecules are polar vs. nonpolar. *A-value is higher for polar molecules*. Second, if two molecules are polar, the one with the *MORE electronegative atom* would have a *higher a-value*.

Iso*baric*

Constant P

Isothermal

Constant T

Iso*choric*

Constant V

Reactions (reactants & products) must pass through moles

Convert to moles using molecular mass (compounds) & atomic mass (elements)

Florescent tubes

Creates potential difference between two plates. Gas ions between plates are accelerated towards the oppositely charged plate. Acceleration increases particles KE absorbing energy by exciting electrons that return back to ground states emitting photons.

At 25 C, any gas density < its density at 0 C

Density = M/V Lower T, Lower V, Higher density. @ *constant V, Mass down if T down*

Sinusoidal function

Describes normal respiration. 1. 0 air flow (no pressure difference). 2. Pressure in drops, breathing in increases, constant flow in the middle and as the lung gradually stops expanding, airflow in gradually decreases until it reaches zero again. This is the sine function of breathing.

Percent change (if value 2 is added to value 1)

Difference between Value 2 & value 1 divided by value 1

Dipole moment is related to electronegativity

Dipole moment represents the degree of sharing between two atoms in a bond.

Atomic model

E= Z^2/n^2 E: principle energy level Z: nuclear charge n: electronic energy level

qE= - mg

Electric force (upward) = gravitational force (downward)

Electron spin number (ms)

Electrons 1st *point ↑*, then as they fill, they point down. ↑ ↓ ↑ ↓. First is +1/2 & second is -1/2.

Helium is larger than Hydrogen (size exception)

Electrons in the n = 1 level repel each other MORE than n = 2 electrons.

Molecular formula

Empirical formula x whole number ratio of MM to empirical mass.

Ionization energy *E (g) = E+(g) + e-*

Energy needed to remove the OUTERMOST electron from the atom in its gas phase. It turns the atom into a *cation*.

Electron affinity *E(g) + e- = E- (g)*

Energy of atom *gaining an e-* (gas phase). It measures an element's *tendency to gain an electron*. It is similar to *reduction potentials* More (-) → more electron affinity (energy released, favorable)

Physical change involves breaking H-bonds (H2O), ionic (, salts, i.e. NaCl), intermolecular (CO2), but never covalent because that's a chemical change

Exception, diamond is a network solid entirely made of covalent bonds. When it melts, they break.

4s orbital is larger than 3s orbital

Explains higher ionization potential of Na (vs. K)

1 Hemoglobin contains 4 Fe atoms

Ferrous is the active form of iron in Hb

What solution has the HIGHEST boiling point?

Find i of kim

What is the [Cl-] after mixing 50 ml 0.1 M KCl (aq) with 25 mL 0.2 M MgCl2 (aq)

Find the weighted average of the two solutions: (2 thirds 0.1 M) + (1 third 0.4 M) = .0667 + 0.133 =~ 0.2 M Cl-C

Collision *force*

Force exerted by gas particles during collision with walls. *Increases by* increased *T* (velocity *↑*, momentum *↑*).

Vapor pressure

Force/area above the liquid surface exerted by molecules formed upon evaporation of the liquid.

*Halogens (VII)* Nonmetals. Form *covalent* molecules *with nonmetals*

Form *ionic* compounds *with metals.* *Strong oxidizing agents* as neutral atoms (*become -1 anions *with a filled octet). *Reactivity decreases* as they go *down*. Mostly *di*atomic.

Supercritical fluids

Free moving molecules with greatest density in the bottom of the container (like a liquid), but the material fills the whole container (like a gas). Their density is between the gas's & liquid's.

Freezing point depression

Freezing point decreases as soluble impurities are added to solution.

Light frequency is correlated with Energy linearly (& velocity squared)

Frequency is correlated with the *velocity squared*, so the relationship here is a curve, not linear.

Electrochemical cell free energy equation

G= *-*nFE

Loss electrons = oxidized. Oxidation state increases

Gain electrons = reduced.

Oxidation Loss of electrons by an atom. oxidation number UP.

Gains bonds with oxygen. Loss of bonds with H. Occurs at the *anode* Catabolism *Anox*

Battery

Galvanic: when used to release voltage (discharges current). Electrolytic: charging (absorbs current/ recharges voltage).

For lungs with a tidal volume of 400 ml and a total volume following normal expiration of 1200 ml. how does the internal pressure change to cause inspiration? 1. Increase by 33% 2. Increase by 25% 3. Decrease by 33% 4. Decrease by 25%

Gas flows from high to low P, so for inspiration to happen, internal pressure has to be LESS. Notice that TV is 400 & expiration is 1200. This gives a total of 1600 ml. The decrease would be 400/1600 which is a quarter. 1200 ml is NOT the total volume

Vapor *@ eq w/ liquid*

Gas particles in equilibrium with the liquid phase (temporary exist as gas until condensing back to the favorable phase)

*Less* electronegative atom

Gets a *partially (+) charge*. They lose electron density.

Reducing agent (*e- leave it*) LiAlH4, NaBH4, Pd/H2 N2H4, OH-, NADH, FADH2

Gets oxidized. Causes reduction. *((((Rich in H & rich e-))))*, poor in O. Metal in low oxidation state

Oxidizing agent (*e- come to it*) CrO3, H2SO4, KMnO4, OH- RCO3H, O3, NAD+, FAD+

Gets reduced. Causes oxidation. *O rich*, poor in H, *e- poor* Metals in *high* oxidation state.

Reducing agent

Gives up electrons (i.e. Group I metals)

*Electrolytic (voltaic) cell* Thermodynamically unfavorable. Energy is added (voltage source must exceed natural voltage).

Greater voltage source dictates electrons flow direction. The *poles of the lower battery are reversed* by the electrons flow force. Electrons flow in a counterclockwise direction (charging the lower battery).

HF vs. H2O

HF has a lower BP because of its lesser degree of H-bonding. H2O has oxygen with 2 lone pairs and 2 Hs that can H-bond, so both Hs & lone pairs can H-bond. HF 3 lone pairs, but only 1 hydrogen on the fluorine, so one H-bond per HF molecule.

Mass spectroscopy 2

Heavier particles have LARGER radii. What if the heavy particle is overshooting? Increase the magnetic field, bend it closer so the detector can detect it. *The smallest radius is associated with the SMALLEST species*

*Altitude, temperature & gases*

High altitude*: 1. Low atm pressure 2. Low [Gas] *Low altitude*: 1. High atm pressure 2. High [Gas] 2. Higher partial pressure of gasses (i.e. O2) *T ↓* gas density ↑ → *[ ] ↑*

Why is Hg used in monometers

High density, low compressibility

Underwater

High external pressure (more air moles needed to fill lungs). Higher [air]. High air viscosity (denser air).

Adhesion force

Holds water & glass.

S block

I Alkali metals II Alkaline earth metals

*FONClBrIS+++++++CH-------* Lists the elements in order of electronegativity from highest to lowest. (*H oxidation number*)

If *H* is bonded to anything *Left to C* in FONClBrISCH it will be *+1*. If it is bonded to *C it will be 0*. If it is bonded to anything that is *not in the list* it will be *-1*.

If 5 parts water are added to one part 0.60 M aq compound, what is the new absorbance?

If 5 parts water are added to one part solution, the new volume would be 6X the original volume, so the new concentration would be 1/6 of the original concentration.

Electronegativity The tendency to hold shared electrons with another atom within a bond. *Clean trend, it has no exceptions* (like other trends do)

If e-negativity has similar values: bond is covalent (1.0 e-negativity) If E-negativity exceeds a difference of 2.0, the bond is ionic.

Collision frequency Rate @ which molecules collide with each other & walls.

Increase by: Temp *↑* [particles] *↑* mean free path *↓*

Zeff

Increases LEFT to RIGHT Takes into account: 1. Attraction with protons. 2. Interactions with neutrons. 3. Repulsion (shielding) due to core electrons.

During expiration

Internal pressure > atm pCO2 > CO2 in air

*Phase change* Physical process (not chemical). Only interactions between molecules change. Reversible process.

Involve enthalpy & entropy changes. Endo or exothermic. Results in volume or shape change.

Composition reactions

Involve the combining of reactants to form a product. *Reactants > products*. Entropy decreases. More bonds are formed than broken.

Electrochemical cells are cyclic

Ions must flow *to balance charge difference* caused by electrons flow.

Bomb calorimeter (energy change measurement)

Isolated system.

A sample emits light of the *same frequency*

It ALWAYS absorbs the *same color* of light. *Regardless* the solution's temperature or concentration.

Nuclear charge (Z)

It affects energy levels around it.

*Conductivity in water*

It depends on the *# of ions* present in the *aq*ueous solution. *More ions in solution = more conductivity*

What does it mean that Δh is 317 torr?

It means the pressure difference is 317. Atm pressure = 760 torr Gas pressure = 760 - 317 = 443 torr

*Half-filled or filled shells* add to the stability of the element

It would *require more energy to ionize* these species.

Voltage

Joules/ Coulombs. Jewels per Ku-lamb

KE forms

KE: gas > liquid > solid Vibrational & Rotational: all phases Translational: gas & liquid phases.

More *electronegative* atoms *take all electrons* in a bond

Less electronegative atoms get none of the bonding electrons

Water vapor vs. oxygen gas

Liquid water is the more favorable phase, so we call the gas phase of water "vapor". Oxygen's favorable phase is gas, so we call it gas.

Being ionized

Losing electrons

*Reduction* *Gain of electrons* by an atom. Decrease in the oxidation number. *Gains of* bonds with* H.*

Loss of bonds with oxygen. Anabolism Occurs at the *cathode* *RedCat*

Low atm = low [gas]

Low T = high [gas]

Voltage & electron affinity Electrons transfer direction

Low → high electron affinity

P block

Lower left side: metal Upper left side: metalloids Right side: nonmetals.

Highest oxidation potential

Lowest ionization energy

Molarity

M= mol/Liters

Solute mass % in a solution

Mass solute/ mass solution

Density

Mass/volume

High oxidation potential

Material that readily loses electrons.

As the volume increases, *concentration decreases*

Mean free path increases (average distance between particles increases).

Average KE

Mean particle energy in a system. Energy ↑, KE ↑, T ↑

HCl vs. H2S BP

Molecular mass is comparable, so insignificant. Both CANNOT H-bond. H2S (bent geometry) has a great BP because it is more *polar* than HCl.

What happens to T & P when a gas is removed from a chamber of a constant V?

Moles of gas are decreasing while V is constant. Pressure decreases. Since *gas removal is endothermic*, T drops.

Avogadro's number

Moles → molecules/ atoms

Momentum equation

Momentum = mas x velocity. Heaviest gases have the highest momentum (if they all have identical T & P)

Standard potentials are usually *reduction potentials*

More (+) the reduction potential → stronger oxidizing agent (easiest to reduce).

Avogadro's Law

More moles, more volume.

Longest lifetime of a galvanic cell

Most anode *metal* & cathode *cation*. These are the two reactants. Anode cation is NOT a reactant.

Typical compound phase diagram

Most compounds can be compressed from a liquid into a solid at a constant temperature. liquid region contains *liquid & vapor*

*Ionic bond (complete e- transfer from metal → non-metal)* Unequal electron sharing *2.1* electronegativity

Naming *ionic compounds*: Transition metals: metal (I, II, III...) Small charge (-ous), greater charge (-ic) *Non*metals (*-ium*)

Effective nuclear charge

Net charge exerted upon the valence electrons. L-R: Zeff is higher because you add a proton and electron, a proton is bigger and stronger.

Ionization energy except

Nitrogen has a higher IE than oxygen, because it loses its half-filled p orbital upon ionization. Oxygen GAINS half-filled upon ionization.

Lower ATM pressure *lowers BP*

No effect on vapor pressure.

Pauli's exclusion principle

No two electrons have the same set of quantum numbers (n, l, ml, ms)

Noble gases (VIII)

Nonmetals. Form *no bonds* *Mono*atomic.

Real gases law

Notice that if you reduce the pressure in half, the ideal gas would have a doubled volume. However, because the gas is real, the increase in volume would be *a little less than double*.

Atmospheric pressure *DOESN'T* affect Vapor PRESSURE

ONLY *TEMPERATURE* affects *P vapor*. P vapor is the same at ANY altitude

If 2 variables, i.e. [ ] & length are correlated, then if one doubles the other doubles as well.

ONLY length would be relevant in the second variable, even if width was changed. Only changes in length are correlated.

Coffee cup calorimeter (enthalpy measure)

Open system (gas can escape to equalize pressure. Constant pressure is maintained).

Amorphous

Opposite to crystalline

Electrochemical line notation

Oxidation (L) to Reduction (R) L-R: anode to cathode. Reactants to products.

Combustion analysis apparatus

Oxidizing an unknown with excess oxygen (to ensure complete combution), then separate and collect all the oxidized products.

Vapor pressure graph

P vapor vs. T (exponential graph). *Tip* of the curve is where the *graph ends*, it's where the NORMAL BP is at *760* torr

Boyle's Law

P1V1 = P2V2

Electron spin pairing

Paramagnetic: unpaired electrons (radicals in organic chemistry), it is susceptible to magentic fields. Diamagnetic: all electrons paired.

If Light & Heavy gases effuse from a container, over time:

Partial pressure of both gases decreases because they're escaping the container. The relative abundance (X) of the heavy gas increases.

Concentration

Particles #/volume

Adiabatic

Perfect insulation (no heat exchange, constant q)

Osmotic pressure

Pi: osmotic pressure M: molarity i: ionization consant R: energy constant T: kelvins

Manometer

Pressure applied on the R side is higher. Δ P is proportional to Δh

Quantum numbers 4L+2 → max number of e- in a subshell (L) 2L + 1 → number of orbitals (ml per l) value. n + L → subshells ranking (Aufbau)

Principle (n): 0+ (*shell level*) Angular momentum: (l): orbital shape, value of 0 or more. Magnetic (ml): orbital orientation (-l to +l), including 0. Spin (ms): electron rotation, +/- 1/2

Colligative properties

Properties of a solution affected by [soluble impurity]

Decomposition reactions

Reactants decompose to form MULTIPLE products. *Reactants < products* Entropy increases. More bonds are broken (than formed).

Galvanic cell Cell stops when voltage = 0

Reactants: 1. Anode metal 2. Cathode *cation*.

Redox reactions Oxidation is loss of electrons. Reduction is the gain of electrons.

Reducing agent (*reductant*) the atom that *causes reduction* of another atom. Oxidizing agent (*oxidant*): atom (or compound) that *gains* electrons and *causes oxidation.* The oxidation state MUST CHANGE in the redox reaction.

Electroplating

Reducing ions in solution onto the surface of a conducting material. Reduction at the cathode. Cathode *gains a thin film of reduced metal* on its surface. Gold-plated jewelry, platinum-plated carbon matrices...etc.

Volume

Region within container walls. V of gas in open environment is undefined. Liters

1 liter of which vapor is the most massive?

Remember the volume of the gas is relatively constant (~22.4L/mole at STP). So the compound with the *HIGHEST MW* would be the *most massive*.

Transition metals *lose 4s e-s first*

Remember, d orbital wants to come close to half-filled or fully filled orbital.

Using PV = nRT to find MW

Remember, if they're asking about the moles, n= PV/RT. However, if they ask about MW (grams/mole), the equation would be *flipped* to RT/PV.

The element that produces the *highest transition energy* is usually associated with a high energy *color* in the spectrum (closer to the *violet end*)

S-block cations size ↑, their electronic transition E ↑

*Galvanic cell* Discharge voltage (harness energy of redox rxns). Negative delta G. (+) emf Anode to Cathode. e- flow L to R (anode to cathode) thru wire.

Salt bridge for spectator anions to go from CATHODE TO ANODE. Spectator anion (chloride, nitrate): high solubility and lack base properties. Anode dissolves away. Cathode plates out. [Ions] in cathode solution are increased or [ions] of anode solution are decreased to *increase voltage*. Multiple cells in series are used to increase the voltage significantly.

Allotropes

Same elements in different forms (mostly solids with varying connectivity of their matrices)

Positron

Same mass as an electron, but POSITIVE (electron's opposite)

Central atom geometry

See TBR P. 134 *Geometric family*: everything attached to the central atom (including nonbonding electron groups). *Shape*: only bonds with the central atom.

Which solution would have the GREATEST salt concentration?

Solutions with: 1. MOST *moles* of salt (find one with *lowest MW*) 2. In the LEAST *volume* of solution.

*Respiration* Step 1 (diaphragm contracts): V lung up, P lung ↓, P internal < P external

Step 2 (air in): n air ↑, P lung ↑, P int = P ext Step 3 (diaphram relaxes): V lung ↓, P lung ↑, P int > P ext

Carbon monoxide

Strong reducing agent. Binds tightly with metals.

Oxidation number is 0 for PURE elements (i.e. metallic Na)

Strongest base has the lowest oxidation state (i.e. CrO > CrO2 or Cr2O3)

STP

T = 0C

Standard conditions

T = 25C

T vs. KE

T ↑, KE ↑

*TBR Gases & Gas Law*

TBR Gen Chem *Section V*

Metallic character trend

The *bigger* the radius of the metal, the *more metal character* it has

How is the GREATEST DILUTION measured?

The *largest added solvent : initial solution ratio*

Electronegativity & lone pairs

The *more electronegative* species pushes *electrons away* from themselves & give the other species *(less e-negative)* a *(+)* charge.

Vapor pressure (*T*-dependent) Independent of the (shape & volume) of the container.

The *rate* of vaporization is GREATER with greater SURFACE area. However, *Vapor pressure* is the *SAME* in both containers.

Beer's law When EM radiation is passed thru a solution, the solute may absorb some of the light in a specific wavelength range.

The absorbance intensity varies with [solute]. Light *absorbance* is proportional to *[solute]*. (Abs. x V) initial = (Abs. x V) final

Galvanizing

The addition of a more reactive metal to be preferentially oxidized over the metal preserved. A thin, reactive metal plate is added to the surface of the steel to prevent iron in steel from rusting away in boats. The metal used is usually *slightly* more oxidizable than the plated metal (i.e. Zn plated over Fe).

*Thomson Experiment* Applied electric field perpendicular to a beam of electrons.

The beam deflected based on field strength & magnitude of deflection. Found out there were two opposite charges in the field (different orientation)

*Why is n = 1 to n = 2 transition has the highest energy?

The bigger n, the smaller the Energy. As the value of n increases, the energy levels become CLOSER to each other.

Density of a material depends on the closeness of the particles of which it is composed.

The closer particles pack, the denser the material would be.

Atomic size

The distance from the nucleus center to the exterior of the valence electron cloud.

Ionization energy can predict the oxidation potentials of an element

The easier to ionize is the easier to oxidize. Easier loss leads to a larger (more +) oxidation potential. *Low IE correlates* with smaller (*more negative reduction potentials*) of the formed cation.

Which of the following would result in a 10-fold dilution? 1. 9 parts solvent with 1 part solution. 2. 10 parts solvent with 1 part solution. 3. 10% solvent with 90% solution. 4. 91% solvent with 9% solution.

The final solution should be 10% the original, so the first choice is right (9 parts solvent + 1 part solution = 10 parts new diluted solution). 1 part solution (original) is 10% of 10 parts of the new solution (new).

Boiling point and nucleophilicity are related to the gas mass

The gas *closest to the ideal gas* has to have *low a & b* values.

Surface tension

The liquid's resistance to increased surface area. *Intermolecular forces* or *MW* increase *viscosity.*

Cations are smaller than neutral atoms (i.e. Na+ ions in CNS)

The loss of electrons allows it to compact more tightly (diminished repulsion associated with the missing electrons).

Coordination number

The number of atoms attached to the central atom within a molecule (BF3 has a coordination number of 3). It does NOT count the lone pairs.

Combustion reactions (A special type of redox rxns.)

The oxidizing agent is a gas. The products are oxides. Examples are hydrocarbons & carbs into CO2 & water.

Reference standard of emf 2H+ → H2 gas

The reduction of 2 protons (H+) to form hydrogen gas (H2). emf of the reference = 0 volts.

*Heating curve* T remains constant during phase change (energy used to break intermolecular forces, not increase KE).

The slope of the / line is inversely proportional to the material heat capacity. *The flatter the line, the greater the heat capacity*

Two solutions with the same salt dissolved into the same solvent.

The solution with the *GREATEST [CONCENTRATION]* will have *GREATER*: *1. Density* *2. Molality* *3. Molarity*

Diffusion

The* dispersion* of a particular gas through a container and is *concentration-dependent*. *Most rapid* when mean free path is *larger* and KE is *greater. * Does NOT involve a pore.

*Alkaline earth* metals Strong reducing agents (readily lose electrons). They are NOT as reactive as alkali metals. React with high electron affinity elements or compounds. Reactivity increases increase as they go down.

Their cation form is * not as soluble in water* due to a small radius and +2 charge. Their react favorably with water (except Be) to form metal hydroxide and H2. *M(s) + 2H2O → M(OH)2(eq) + H2 (g)* All form oxides (MO) when oxidized by oxygen gas. *2M (s) + O2 (g) → 2MO (s)* They can be *oxidized by N, halogens, H*.

Alkali Group I metals Strong reducing agents (as neutral elements), they become +1 cations. *Reactivity increases ↓* (easier to lose e-).

Their cation forms are *very water soluble* with any anion & react favorably with water to *form metal hydroxide* and *H* gas. *2 M(s) + 2H2O(g) → 2 MOH (aq) + H2* Also, they can be oxidized into cations by: 1. Halogens 2. Nitrogen 3. Hydrogen

Group I & II metals

Their cations have very NEGATIVE reducing potentials.

Liquids have the highest heat capacity of all phases

They are compressible. Liquid density decreases at T increases (with the exception of water at 0-4C).

Molecules only evaporate from the surface of a liquid

They tend to *evaporate from the corners* (fewer neighboring molecules, fewer intermolecular forces).

Photoelectric effect

Think ionization energy of metals

Greatest sublimation point?

This means requiring MOST energy to reach the temperature to sublimate (*highest MW*)

High ionization energy

Tightly held electrons (opposite of having high oxidation potentials)

Lifetime of the excited state

Time an electron remains in the elevated energy level (picosecond to nanosecond in length)

Temperature

Total KE of a system Kelvin.

n = 1 to n = 2 transition is of a *higher energy* than n = 2 to any other level.

Transition from n= 2 to n= 3 is higher than transition from n = 3 to any higher level.

Electrolysis

Unfavorable reaction run by adding voltage. It generates less favorable products. Used to obtain pure gas samples (O2, Cl2) & reduced metals naturally found in an oxidized state. Applied voltage must *overcome* the negative voltage of the unfavorable rxn (only *slightly* higher to avoid multiple products).

As a liquid temperature increases, its vapor pressure increases EXPONENTIALLY

Unrelated: Heat capacity (q) = mcΔT. m is mass. ΔT is change in temp (C or K).

Supercritical fluid oxygen

Used to completely oxidize materials that do not burn cleanly under standard conditions with O2 gas.

Supercritical carbon dioxide

Used to decaffeinate coffee. Dry cleaning.

Charles's Law

V1/T1 = V2/T2

Covalent forces would need electrons sharing.

VDW forces are too weak.

Density of solution

Varies with temperature.

Nobel gases

Very low electron affinity (they don't need them)

Technetium (Tc)

Very unstable radioactive element.

Tidal volume

Volume of air entering or leaving during normal breathing. Lung volume is ALWAYS HIGHER than tidal volume because: TLV = RV + dead space + TV

Combustion reaction products

Water & CO2 (no solid formed)

Osmotic pressure tube

Water flows to the side with MORE SOLUTE. Water movement stops when: Hydrostatic P = Osmotic P. P hydrostatic = pgΔh p: density Δh: difference in the uneven U shape.

ΔH sublimation = ΔH fusion + ΔH vapor

Water heat capacity = 1.0 cal/g K

Water trivia Its liquid form is DENSER than its solid form. *High heat capacity of water = absorbs most energy with least T change*

Water is *densest at 4C*. Ice can be compressed to liquid water. Extremely high BP compared to similar MW compounds due to *H-bonding*. Water has the *densest H-bonding of any compound*

Freezing point depression occurs because solutes disrupt crystalline structure formation.

Water moves from solution of low osmotic pressure to solution of HIGHER osmotic pressure.

Conductance

Water needs IONS to be able to conduct an electrical current. Pure water is NOT conductive. Conductance is DIRECTLY proportional to [salt] in soluton. Electrical conductance is observed ONLY with ionic solutes.

If given a reduction half-potential table and is asked for strongest reducing potentials?

What's requested is the species that gets oxidized, so the values in the table should be *reversed*. Then look for the most positive value.

Carbonate (pic is wrong?)

When organic compounds get broken down, carbonate is usually produced in aqueous environments. Carbonate is an anionic form of CO2.

Aufbau principle

With the *Aufbau's exception* of half-filled d shell in *Cr* & filled d-shell stability in *Cu*.

Raoult's Law

Xi: mole fraction of the component in solution (not vapor state). P1: vapor pressure of a pure sample of the component under same conditions. Vapor pressure is calculated as (partial vapor pressure) since it is of only one component.

It takes MORE energy to make vapor than to melt a solid

You can reason that condensation releases more heat than freezing (i.e. vaporization requires more ΔH than melting).

Molality

does NOT change with temperature

Oxidation 3

e- flow *from the anode*

Reduction 2

e- flow to cathode

Ferric

ric is more oxidized than "ous*

Phase enthalpy

ΔH sublimation > ΔH vaporization > ΔH fusion.

Temperature ↑, Vapor pressure ↑

ΔH vaporization *↑*, P vapor *↓*

Pressure difference equation

ΔP = ρgΔh

Phase entropy

ΔS sublimation > ΔS vaporization > ΔS fusion.