In a 0.10 M solution of H2Se, the Se2- concentration is:

  (a) [Se2-] = 0.10 x Ka2 = 1.0 x 10-11       (b) [Se2-] = Ka2 = 1.0 x 10-10

   (c) [Se2-] = (0.10 x Ka2)1/2 = 3.2 x 10-6   (d) [Se2-] = (0.10 x Ka1)1/2 = 4.1 x 10-3

     (e) none of the above

 When NH4Cl is added to an 0.10 M NH3 solution, the pH of this solution:

(a) increases 

(b) decreases

 (c) remains the same

  (d) increases at first and then decreases.

     (e) decreases at first and then increases.

What are the three States of matter? 

 In a 0.10 M solution of H2Se, the Se2- concentration is:

  (a) [Se2-] = 0.10 x Ka2 = 1.0 x 10-11       (b) [Se2-] = Ka2 = 1.0 x 10-10

   (c) [Se2-] = (0.10 x Ka2)1/2 = 3.2 x 10-6   (d) [Se2-] = (0.10 x Ka1)1/2 = 4.1 x 10-3

     (e) none of the above

 Which of the following acid-base reactions should go more or less to completion?

(a) HClO4(aq) + OCl-(aq) ➝ ClO4-(aq) + HOCl(aq)

 (b) HF(aq) + I-(aq) ➝ HI(aq) + F-(aq)

   (c) H2SO3(aq) + SO42-(aq) ➝ H2SO4(aq) + SO32-(aq)

    (d) H2S(aq) + 2 Cl-(aq) ➝ S2-(aq) + 2 HCl(aq)

    (e) All of these reactions would go to completion, giving high yields of products.

Solutions of each acid are prepared in which the initial concentration of the acid is 0.1000 M. Which of the four solutions will be the most acidic?

(a) HA

 (b) HB 

(c) HC

 (d) HD

 (e) not enough information is provided to answer this question.
 

Ammonia and the ammonium ion form a conjugate acid-base pair.

         NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)

Calculate the pH of 0.10 M NH3 if Ka for the NH4+ ion is 5.6 x 10-10

 (a) 4.7 

(b) 5.1

 (c) 5.7 

(d) 8.9

 (e) 11.1
 

A 0.10 M solution of a weak acid, HA, is found to be 1.50% ionized. Calculate Ka for this acid.

         (a) 1.5       (b) 2.3 x 10-1        (c) 2.3 x 10-5        (d) 2.3 x 10-6

         (e) none of the above
 

 H2Gly is an acid and Na2Gly is a base. On the basis of the values of Ka1 and Ka2 for H2Gly and the values of Kb1 and Kb2 for Na2Gly, would an 0.10 M NaHGly solution be acidic, basic, or neutral? (H2Gly: Ka1 = 4.5 x 10-3, Ka2 = 2.5 x 10-10)

(a) slightly acidic 

(b) slightly basic

 (c) neutral (pH = 7)

  (d) there is no way to predict whether NaHGly is an acid or base.