34.The following pictures represent aqueous solutions of binary acids of the type HA where the water molecules have been omitted for clarity.

Determine the strongest acid of the set.
(A)A
(B)B
(C)C
(D)D

30.The iron content of foods can be determined by dissolving them in acid (forming ), reducing the iron(II) to iron(I), and titrating with cerium(IV): Identify the two half-reactions in the above reaction. (A) (B) (C) (D)

31.For the hypothetical reaction . For this reaction, if the value of x is 4, then the value of y =_________. (A)1 (B)2 (C)3 (D)4

32. Which of the following reactions should be spontaneous under standard conditions? (A) I and II are both nonsponta (B) I is nonspontaneous and I is spontaneous. (C) I is spontaneous and II is nonspontaneous. (D) I and II are both spontaneous.

33.At a certain temperature, Kc equals 1.4 x 102 for the reaction:2CO(g)+O2(g)⇌2 CO2(g) If a 2.50-L flask contains 0.400 mol of CO2 and 0.100 mol of O2 at equilibrium, how many moles of CO are also present in the flask? (A) 0.422 mol (B) 0.169 mol (C) 0.107 mol (D) 0.0114mol

35.What is the second stepwise equilibrium constant expression for phosphoric acid H3PO4? (A) (B) (C) (D)

36.Sodium reacts violently with water according to the equation: 2 Na(s) + 2 H2O(l)→ 2 NaOH(aq) +H2(g) The resulting solution has a higher temperature than the water prior to the addition of sodium. What are the signs of △H° and △S° for this reaction? (A) △H° is negative and △S° is negative. (B) △H° is negative and △S° is positive. (C) △H° is positive and △S° is negative. (D) △H° is positive and △S° is positive. 

37.For the process Assuming that the surroundings can be considered a large heat reservoir at 25°C, calculate for the process at 25°C and 1 atm pressure. Is the process spontaneous at 25°C and 1 atm pressure? (A) (B) (C) (D)

38. In the following reaction the unshaded spheres represent H atoms. Identify the BrΦnsted-Lowry acid/base conjugate pairs. (A)(1)/(2) and (3)/(4) (B) (1)/(3) and (2)/(4) (C) (I)/(4) and(2)/(3) (D) none of the above.

39.An experiment with takes 47.5 hours. At the end of the experiment, 1.90 ng of remains. If the half life is 18.0 hours, how many ng of  were originally present? (A) 2.47 ng (B) 3.05 ng (C) 3.28ng (D) 11.8 ng

40.The functional groups in the molecule below are (A) alkane, aldehyde, and ester. (B) alkane, aldehyde, ketone, and ether. (C) alkane, carboxylic acid, and ester. (D) alkane, ketone, and ester.