What two rates are equal in equilibrium for a standard reaction A + 2B <-> C + 3D and what is Keq?
Kf= Kr. keq = kf/kr = ([C][D]^3)/([A][B]^2)
100
Sum up Le Chatlier's Principle
If a system at equilibrium is disturbed by the change in temperature, pressure, or component concentration, the system will shift to minimize the effect of this stress
100
What is a Bronsted-Lowry Acid?
A proton donor
100
What is the relationship between Kw, Ka, and Kb
Kw = KaKb
100
For a polyprotic acid, which is larger, [ka1 or ka2], and [pka1 or pka2]?
First hydrogen dissociates more easily- ka1>ka2, pka1 < pka2
200
What is the expression for converting between kc and kp? What does "[delta]n" represent?
kp = kc(RT)^[delta]n.
"[delta]n" is the change in gaseous moles
200
For [delta]H < 0, adding heat makes which rate, kf or kr, temporarily larger than the other? Which way does equilibrium shift?
kr > kf. Equilibrium shifts left towards reactants.
200
What is an amphiprotic species? Give a general or specific example.
Species that can act as acid or base. Examples include partially deprotonated polyprotic acids such as HS-
200
Select the stronger base in the following pairs: BrO- or ClO-, BrO- or BrO2-, HPO4^-2 or H2PO4-.
BrO-, BrO-, HPO4^2-
200
Which is the stronger acid in the following pairs and why: HNO3 or HNO2, H2S or H2O, H2SO4 or HSO4-.
HNO3 (more nonprotonated oxygen atoms), H2S (acidity increases down group for binary acids), H2SO4 (HSO4- holds on to the proton more tightly because it is in an anionic state).
300
If Q > K, which way does the reaction go?
Reverse
300
For an endothermic reaction, how does keq change with increasing temperature.
As temperature increased, keq will increase.
300
What is the pOH if [H+] = 10^-5. What is the relationship between pH and pOH?
pH = 5, pOH = 9, pH + pOH = 14
300
Predict which member of each pair produces the more acidic aqueous solution: [Fe2+ or Fe3+], [Al3+ or Ga3+], [F- or CH3-] Explain.
Fe3+ (greater cation charge), Al3+ (smaller radius), F- (more stable than CH3-, and will not react as much with H20 to form OH-)
300
What is the pH of a H3PO4 soln when [H2PO3]- = [HPO3]2-. pka1 = 2, pka2= 7, pka3= 13
pH = (pka2 + pka3)/2 = (7 + 13)/2 = 10
400
What differentiates homogenous and heterogenous reactions?
Same species vs. different species
400
Adding a catalyst effects each of the following how (increase, decrease, the same)? rate of kf, rate of kr, Keq, equilibrium shifts
increase, increase, the same, the same
400
Name 6 of the 7 strong acids
HCl, HNO3, H2SO4, HBr, HI, HClO3, HClO4
400
Name one factor that determines the strength of an oxyacid
electronegativity of the central atom or the number of nonprotonated oxygen atoms in the molecule.
400
WHich of the following acids is most acidic and why: chloroacetic acid, dichloroacetic acid, trichloroacetic acid.
trichloroacetic acid because increasing electronegativity around the center atom.
500
For reaction A + 2B <-> C + 3D, with initial concentrations [A] = [B] = 1M, give the quadratic ICE box equation, but do not solve.
K = [(3x)^3(x)]/(1-x)(1-2x)^2
500
For the reaction, PbCl2 <-> Pb + 2Cl, adding AgNO3 does what to the system? no change, shift left, or shift right? Why?
AgCl precipitates, equililbrium shift right.
500
Name 6 of the 8 strong bases.
Group I hydroxides (Li, Na, K, Rb, Cs) and Group II metals (Ca, Sr, Ba)
LiOH, KOH, NaOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
500
State the trend in the acidity of binary acids across a row of the periodic table. State the trend in acidity going down a group in the periodic table.
The acidity of binary acids increases from left to right in a given row on the periodic table. The acidity increases from top to bottom in a given group on the periodic table. Follows trends for electron affinity/ionization energy
500
Why is the pH for [HCl] = 1E-8 NOT 8?
The autoionization of water must be accounted for. [H+] = 1E-7 + 1E-8 = 1.1E-7. pH = 6.95