test 3
Calculate delta s rxn for the following reaction. the s for each species is shown below the reaction (200.9 130.7 219.3)
-112.3J/K
use hess's law to calculate delta g rxn using the following information (+489.6 +463.4 -199.5)
-225.7
determine delta g rxn using the following information (delta H = -11 kJ delta S = -17.4J/K)
-5.8kJ
determine the molar solubility of PbSO4 in pure water. Ksp(PbSO4)=1.82x10^-8
1.35x10^-4
calculate the Ksp of Fe2S3 in pure water. The molar solubility is 1.05x10^-18
1.40x10^-88
Calculate the pH of a buffer thats .058 M HF and .058 M in LiF the Ka for HF is 3.5 * 10-4
3.46
a 1.50 buffer solution is .250 M in HF and .250 M in NaF calculate the pH of the solution after the addition of .0500 moles of solid NaOH. Assume no volume change upon the addition of base. The Ka for HF is 3.5 * 10-4
3.57
determine the equilibrium constant for the following reaction at 298K (delta g= -90.5)
7.31x10^15
a 100 mL sample of .20 M HF is titrated with .10 M KOH. Determine the pH of the solution after the addition of 200 mLof KOH. The Ka for HF is 3.5 * 10-4
8.14
Which of the following is true? a. The equivalence point is where the amount of acid equals the amount of base during any acid-base titration b. At the equivalent point, the pH is always 7 c. An indicator is a plot of pH vs. the [base]/[acid] ratio d. A titration curve is a plot of pH vs. the [base]/acid] ratio
A
Which of the following statements is true? a) endothermic processes decrease the entropy of the surroundings, at constant T and P b) entropy is not a state function c) exothermic processes are always spontaneous d) endothermic processes are never spontaneous e) none of the above
A
Which one of the following statements is TRUE? A) A buffer resists pH change by neutralizing added acids and bases B) A buffer can absorb an unlimited amount of acid or base C) A buffer is an aqueous solution composed of two weak acids D) A buffer does not change pH when strong acid or base is added E) non of the above
A
consider the following reaction that has negative delta h and positive delta s. which of the following statements is true a) this reaction will be spontaneous only at high temperatures b) this reaction will be spontaneous at all temperatures c) this reaction will be nonspontaneous at all temperatures d) this reaction will be nonspontaneous only at high temperatures e) its not possible to determine without more information
B
Define buffer capacity.
Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness.
Which of the following statements is true? a) delta s uni is always greater than zero for a nonspontaneous process b) exothermic processes decrease the entropy of the surroundings c) entropy is an extensive property d) entropy is not temperature dependent e) none of the above are true
C
if delta G < 0 which of the following statements is true a) the reaction is at equilibrium b) the reaction is not spontaneous c) the reaction is spontaneous d) not enough information is given
C
Identify the change in state where the delta s decreases
Gas to Solid
If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.74, what is true?
HCHO2 = NaCHO2
which of the following compounds will have the highest molar solubility in pure water.
MgCO3, Ksp=6.28x10^-6
Give the expression for the solubility product constant for PbCl2
[Pb^2+][Cl^-]^2
which solution is a good buffer system
a solution thats .10 HC2H3O2 and .10 M LiC2H3O2
consider the following reaction at constant P. use the information here to determine the value of delta s surr at 298K. predict whether or not this reaction will be spontaneous at this temperature
delta s surr = -223J/K, reaction is not spontaneous.
when tritrating a weak monoprotic acid and NaOH at 25C
pH will be equal to 7 at the equivalence point
when tritrating a strong monoprotic acid and KOH at 25C
pH will be greater than 7 at the equivalence point
Which of the following processes has a delta s>0
sodium chloride dissolves in pure water
