7. A solution contains the ions Ag⁺, .Dilute solutions of NaCI, Na₂SO₄, and Na₂S are available to separate the positive ions from each other. In order to effect separation, the solutions should be added in which order?
(A) Na₂S, NaCI, Na₂SO₄
(B) Na₂SO₄, NaCI,Na₂S
(C) Na₂SO₄, Na₂S, NaCI
(D) NaCI, Na₂S, Na₂SO₄
(E) NaCI, Na₂SOa,Na₂S

3. Calculate the pH of 0.10 M NH4CN.() (A) 5.79 (B)8.21 (C) 8.87 (D) 5.13(E) 9.23

4. Compounds X and Y have the same mass, but compound Y has two more atoms in its structure. Which statements must be true? (A) Cv for compound X is greater than Cv for Y (B) Cv for compound X is less than C, for Y (C) Cpfor compound X is greater than Cp for Y (D) Cp, for compound X is less than Cp for Y (E) B and D

5. Which of the following gases is/are present in the fuel obtained after coal gasification? I: octene gas； II: synthetic gas； IIl: methane gas； IV: mercaptan gas； V propane gas (A) I and IV (B) I and V (C) I, II and IIl (D) II, IV, and V (E) II and Ill

6. When the equation for the following reaction in basic solution is balanced, what is the sum of the coefficients?(A) 20(B) 10 (C)8 (D)13(E)11

8. When NH3(aq) is added to(aq), a precipitate initially forms. What is its formula? (A) CuO (B) Cu(NH3) (C) Cu(OH)2 (D) Cu(NO3)2 (E)

9. Order the following according to increasing rate of effusion: (A) CH4 ＜NO2＜NO＜F2＜CI2(B) CI2＜F2＜NO2＜CH4＜NO(C)CI2＜NO2＜F2 ＜NO＜CH4(D) CH4 ＜NO＜F2＜NO2＜Cl2(E) F2 ＜NO ＜CI2 ＜NO2＜CH4

10. As water is heated, its pH decreases. This means that (A) [OH-] ＞[H+] (B) [H+]＞ [OH-] (C) the water is no longer neutral (D) two of these are correct. (E) none of these is correct.

11. A 100.0-mL sample of 0.2 M (CH3)3N is titrated with 0.2 M HCI. What is the pH at the equivalence point? (A) 5.4 (B)7.0 (C) 10.3 (D) 3.1 (E) 9.9

12. You have a solution of 0.10 M CI- and 0.10 M . You add 0.10 M silver nitrate dropwise into the solution. . Which of the following will precipitate first? (A) silver nitrate (B) silver chromate (C) cannot be determined from the information given (D) silver chloride (E) none of these

13. A 0.012-mol sample of Na:SO, is added to 400 mL of each of two solutions. One solution contains 1.5 x 103 M BaCh； the other contains for CaSO, = 6.1 x 10S. Which of the following statements is true? (A) both BaSO4, and CaSO4 would precipitate (B) not enough information is given to determine whether precipitation would occur (C) CaSO4 , would precipitate, but BaSO4, would not (D) BaSO4, would precipitate but  CaSO4  would not (E) neither BaSO4, nor  CaSO4 , would precipitate.