{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

19 Acid & Base Ionization Constants

19 Acid & Base Ionization Constants - Which one of...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 1 Which one of the following is not correct? If all are correct, respond (E) A) A reaction as written (I+II III+IV) has both a forward direction and a reverse direction. B) A reaction has both an exothermic direction and an endothermic direction. I+II III+IV with H<0 is exothermic. III+IV I+II with H>0 is endothermic. C) When the temperature decreases, equilibrium shifts toward the exothermic direction. D) When the temperature increases, equilibrium shifts toward the endothermic direction. E) A – D all are correct statements. 1 ln( ) o o H S K R T R   2 How good is enzyme catalysis for the production of ammonia? Compare the equilibrium constants at 300 K and 800 K (used in the commercial process). N 2 (g) + 3H 2 (g) 2NH 3 (g): H o = - 92 kJ/mol, S o = - 199 J/mol K, G o = - 32 kJ/mol R = 8.314 J/mol K What did you get? A) 300 K = 4.2 x 10 5 and 800 K = 4.1 x 10 -5 B) 36.9 and 23.9 C) 12 x 10 3 and 8 x 10 -3 D) 13.0 and 10.1 o o o ln( ) G = H -T S 1 ln( ) o o o G K RT H S K R T R  
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 3 Acid Ionization Equilibrium Constants HA + H 2 O H 3 0 + + A - If K a >> 1 Ionization is essentially 100% Called strong acids K a <1 Only a fraction of the molecules ionize. Called weak acids See values in MSJ Table 16.2. p. 788 K a = [H 3 O + ] [A - ] [HA] 4 Weak Acid Example Weak acids do not ionize completely in water. Equilibrium is reached before the acid has ionized completely into ions. HF(aq) + H 2 O(l) H 3 O + (aq) + F - (aq) Lots of this! Not much of this! K a = [H 3 O + ] [F - ] [HF] < 1 Acid Conjugate Base
Image of page 2
3 5 Base Ionization Equilibrium Constants B + H 2 O BH + + 0H - If K b >> 1 Ionization is essentially 100% Called strong bases K b <1 Only a fraction of the molecules ionize.
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern