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Acids & Bases
Equilibrium
Miscellaneous
Old Test Questions
Concept Query
100
Classify Sr(OH)2
What is a strong base?
100
Calculate Kp for H2O(g) + ½ O2(g) ⇔ H2O2(g) at 600 K using the following data: H2(g) + O2(g) ⇔ H2O2(g) Kp = 2.3 x 106 at 600 K 2 H2(g) + O2(g) ⇔ 2 H2O(g) Kp = 1.8 x 1037 at 600 K
What is 9.8E24?
100
Which of the following substances is incorrectly described? (A) HCl, Arrhenius and Bronsted-Lowry acid (B) NaOH, Arrhenius and Bronsted-Lowry-base (C) NH3, Bronsted-Lowry base (D) H2O, Arrhenius and Bronsted-Lowry acid and base (E) HCO3-, Arrhenius and Bronsted-Lowry acid and base
What is E, HCO3- (Not an Arrhenius Base)
100
Based on a reaction profile, the enthalpy of reaction is -220 kJ and the energy of activation for the backward reaction is 520 kJ. What is the energy of activation for the forward reaction in kJ?
What is 740kJ?
100
True or false:Kw=ka*kb
What is True?
200
At 22.0 ºC, Kw = 8.00 x 10-15. What is the pH of pure water at this temperature?
What is 7.05?
200
What is Kc if Kfwd=Krev? Explain with a reaction line.
What is 1?
200
Given that HX is a stronger Brønsted acid than HY in aqueous solution, which is true of a 1 M solution of NaX? (A) It is less basic than a 1 M solution of NaY. (B) It is more basic than a 1 M solution of NaY. (C) It yields a neutral solution. (D) It is more concentrated than a 1 M solution of NaY.
What is A? It is less basic than 1M solution of NaY.
200
A 1.00 L evacuated tank is filled with HI to 1.00 atm pressure. Once equilibrium according to: 2HI(g) <=> H2(g) + I2(g), K = 0.050 is achieved, what is the pressure of HI?
What is 0.69?
200
Explain why solids and liquids are not considered in the determination of Kc?
What is: Liquids are solid concentrations are considered fairly constant and thus are not part of our equilibrium concentration as their change is minimal.
300
Given the following values of pK, which is the weakest acid of those listed in the answers? pKb of NH3 = 4.75 pKa of HNO2= 3.37 pKb of C5H5NH = 8.75 pKa of HBrO = 8.69 pKa of HClO = 7.53 Possible Answers: HNO2, HBrO, HClO, NH4+, C5H5NH+
What is NH4+?
300
What does Dr. Bott constantly chew? A. British gum B. Paper C. Laffy Taffy D. His own tongue E. Nothing, it’s just an intimidating masticating motion
Unknown. Let me know if you find out.
300
What is the conjugate base of hydrogen sulfate?
What is SO4-?
300
Explain, conceptually, what the half-equivalence point on a WA/SB titration curve is. Why is it significant?
What is: Point at which we’ve added enough SB to neutralize half of the WA moles. We have created an equal amount of conjugate base (WB), creating a 1:1 buffer solution which is fairly resistant to change.
400
25.0 mL of 0.10 M C2H5NH2 (ethylamine) is titrated with 9.00 mL of 0.15 M HCl. Given that the Kb of ethylamine is 6.5 x 10–4, what is the pH of the solution?
What is 10.74?
400
True or False: A reaction’s kc is dependent on the initial amounts present.
False. Kc is a ratio.
400
A 0.20 M solution of the hypothetical weak acid HZ was found to have a pH of exactly 3.0. The ionization constant, Ka, of the acid is?
What is 5E-6?
400
Consider the reaction shown. Using your knowledge of relative acid-base strengths and equilibrium, determine what you can about the size of Kc for the reaction. HBrO3(aq) + ClO3-(aq) <=> BrO3-(aq) + HClO3(aq)
What is Kc<1?
400
Explain why K2<
As the compound releases its protons, its conjugate base becomes fairly negative and it becomes less likely to release its remaining protons.
500
What is the pH of a 1.0 x 10–8 M NaOH solution?
What is a bit more than 7?
500
What is the value of Kc if PNO2 = 2 PN2O4? N2O4 (g) <=> 2NO2(g) A. (RT PNO2) / 2 (PNO2)2 B. (PNO2)^2 / (2 RT*PNO2) C. 2 (PNO2)^2/ (RT*PNO2) D. (PNO2)^2 /PNO2 E. (PNO2)^2 / (2 PNO2)
What is 2(PNO2)^2/(RT*PNO2)? (C)
500
Arsenic acid (H3AsO4) has Ka values of 2.5 x 10–4, 5.6 x 10–8, and 3 x 10-13. What is the concentration of the HAsO42- dianion in a solution whose initial arsenic acid concentration was 0.35 M?
What is 5.6E-8?
500
A solution of 0.10 M NaIO(aq) has a pH of 8.90. What is the Ka of HIO(aq)?
What is 1.6E-5
500
Explain why the concentration of [OH-] and [H3O+] are never actually 0 in water.
Water molecules are constantly reacting with each other, forming hydroxide and hydronium as they capture or take protons from each other.