GC- gases, solutions, acid-bases

what are the soluble salts?

group 1 metal cations, NO3-, ClO4-, C2H3O2-, NH4+

what are the INsoluble salts?

Ag+, Pb2+, Hg2+, OH-, S(2-), CO3(2-), PO4(3-)

What are the strong acids?

HCl, HBr, HI, HClO4, HClO3, H2SO4, HNO3

What are the strong bases?

Group 1 metal hydroxides, Ba(OH)2, Sr(OH)2, Ca(OH)2

What is the difference between strong, weak, and non- electrolytes?

The ability to dissociate (fully, incompletely, and not at all)

What are strong electrolytes (examples)?

Soluble ionic compounds, strong acids, and strong bases

What are WEAK electrolytes (examples)?

weak acids and weak bases

What are non-electrolytes?

compounds that aren’t acidic OR basic

When are solids and gases most soluble?

Higher temperature for solids, lower temperature and higher pressure for gases

What is a spectrophotometer/what does it do?

Measures how much light is sent in/comes out of a solution

What is Beer’s Law? (definition and formula)

Light absorption is directly proportional to path length and the concentration of the solution. A =elc

Raoult’s Law formula

PA=XAPºA where PA=vapor pressure of solution, XA=mole fraction of solvent, and PºA=pure vapor pressure of solvent

Non-Colligative Properties are (list all)

surface tension, viscosity, solubility, color, density

Colligative Properties are (list all)

vapor pressure depression, boiling point elevation, freezing point depression, osmotic pressure

Definition of boiling point

when vapor pressure equals atmospheric pressure

How does boiling point change with elevation

INcreased elevation = DEcreased atmospheric pressure = lower vapor pressure to reach BP = lower BP

(opposite for decreased elevation, air is denser at lower altitutdes)

How does vapor pressure change with the addition of NON VOLATILE solute

decreases vapor pressure which increases boiling point (high entropy of solute)

What is the boiling point elevation formula

∆Tb=(kb)im where ∆Tb=amount boiling point increases, kb=solvent’s boiling point elevation constant, i=solute’s van’t Hoff factor (number of particles solute breaks into when it dissolves), m = molal concentration of solution

Freezing point depression formula

∆Tf=-(kf)im where ∆Tf=amount freezing point decreases, kf=solvent’s freezing point depression constant, i=solute’s van’t Hoff factor, m=molal concentration of solution

Definition of osmotic pressure

the pressure it would take to stop osmosis from happening

Formula for osmotic pressure

π=iMRT, where π=osmotic pressure (atm), i=van’t Hoff factor, M=molarity of solution, R=universal gas constant (0.0821L*atm/K*mol), and T=temp in Kelvin

Formula involving pressure, force, and area

P=f/a (pressure and area are inversely related)

Boyle’s Law

P1V1=P2V2 under constant temp and moles, P in atm, V in L

Charles’s Law

V1/T1=V2/T2 under constant pressure and moles, T in K, V in L

Avogadro’s Law

V1/n1=V2/n2 under constant pressure and temperature, V in L

Gay-Lussac’s Law

P1/T1=P2/T2 under constant volume and moles, P in atm, T in K

Combined Gas Law

P1V1/n1T1=P2V2/n2T2

Ideal Gas Law

PV=nRT

What is the standard temperature and pressure?

273 K and 1atm for an ideal gas

Kinetic-Molecular Theory of Gases

1. Particles in a gas are in constant, random motion

2. Combined volume of particles is negligible

3. Particles exert no forces on one another

4. Gas molecule collisions are completely elastic (no intermolecular forces)

5. All gases have the same average kinetic energy at a given temperature (average kinetic energy of particles is proportional to temperature in Kelvin)

Dalton’s Law of Partial Pressure

Ptotal=P1+P2+P3… and P1=X1Ptotal where X1=moles of Gas1/total moles

Gas Density (formula)

p=m/v=PM/RT

What are the two values of the ideal gas constant

R=0.0821 Latm/molK or 8.314LkPa/molK

At STP, 1 mole of gas occupies what volume

22.4L

Effusion (definition)

A confined gas escaping through a small hole in its container

Effusion rate (ranking)

gas>liquid>solid, lower molecular weight effuses faster

Graham’s Law of Effusion

r1/r2=sqrt(M2/M1) where r is effusion rate

How many mmHg are in 1atm

760

Lewis definition of acid base

electron acceptor or donator

Arrhenius definition of acid base

dissolves in aqueous solution to H+ or OH-

Bronsted-Lowry definition of acid base

proton donor or acceptor

pH from H+

pH=-log[H+]

H+ from pH

[H+]=10^-pH

OH- from pOH

[OH-]=10^-pOH

pOH from OH-

pOH=-log[OH-]

What is the dissociation constant of water (Kw) at 25ºC

1×10^-14=[H+][OH-]=KaKb

formula for pKa or pKb from Ka or Kb

-log(Ka)

Ka of a strong acid compared to 1

greater than

Amphoteric

a substance that reacts as both an acid and base (ex. water)

Binary acids

hydrogen halides (HI, HBr, HCl, HF)

Oxoacids

contain oxygen (more oxygens better bs stability, ex. H2SO4 >H2SO3)

Formula for neutralization reactions

M1V1=M2V2 (where 1 is acid and 2 is base)

Strong acid + strong base = what kind of salt

neutral salt

Strong acid + weak base = what kind of salt

acidic salt

Weak acid + strong base = what kind of salt

basic salt

Weak acid + weak base = what kind of salt

not a salt!

Henderson-Hasselbalch Equation for pH

pH=pKa+log[A-]/[HA]

Henderson-Hasselbalch Equation for pOH

pOH=pKb+log[HB+]/[B]

In a titration, what is the name of the liquid in the burette? And the Erlenmeyer flask?

Titrant, analyte

Equivalence point

point in titration at which amount of titrant added is just enough to neutralize the analyte solution (mols titrant = mols analyte)

Half equivalence point

midpoint of buffering region when pH=pKa seen when strong acids/weak bases or weak acids/strong bases are combined

What are all the ways to make a buffer?

1. weak acid + salt 1:1

2. weak acid + strong base 2:1

3. salt (conj. base) + strong acid 2:1

4. weak base + salt 1:1

5. weak base + strong acid 2:1

6. salt (conj. acid) + strong base 2:1

Polyvalent acids and bases

can donate or accept more than 1 H+ ion