4 PH3 (g) ➝ P4(s) + 6 H2 (g) The reaction is first order in PH3 (g) and has a rate constant k of 6.28 x 10-2 s-1 . If [PH3] = 0.417 M at time t = 0, at what time will [PH3] = 0.174 M? a. 53.3 s b. 13.9 s c. 38.2 s d. 0.0795 s e. 44.1 s   Tables.pdf Periodic Table with New Elements.pdf

Consider the following electrochemical cell operating at 25oC (Pt is an inert electrode):  Which of the following statement(s) is (are) true when the cell operates spontaneously? (That is, when e- are allowed to flow whichever way they “want” to) 1. The measured voltage would be 0.603 V2. The Pt electrode would be the anode3. The measured voltage would be 1.277 V4. Electrons would move from left to right (—>) a. 1 only b. 3 only c. 1 and 2 only d. 1, 2, and 4 only e. 2, 3, and 4 only

Which of the following would you mix with NH4Br(aq) to make a buffer? a. NaBr(aq) b. HBr(aq)  c. NH3(aq) d. HBrO (aq) e. NH4Cl(aq)

Suppose a chemist starts with an aqueous buffer that contains 0.05 mol of HCN and 0.07 mol of NaCN in a total volume of 1.00 L. What is the pH after 0.03 mol of OH- is added to the buffer?  a. 9.01 b. 9.46 c. 10.92 d. 10.01 e. 8.61

Which one(s) of the following substances is (are) a weak base in aqueous solution?   1. IO-       2. OH-       3. C2O4 -2        4. NH3       5. HCHO2   a. 2 only b. 1 and 4 only c. 1, 2, 3, and 4 only d. 4 and 5 only e. 1, 3, and 4 only

Classify HClO as a strong base, weak base, strong acid, or weak acid, and then answer the following question. What is the pH of a 0.07 M HClO (aq) solution? a. 1.2 b. 8.7 c. 4.3 d. 9.7 e. 5.3

Classify HNO3 as a strong acid, weak acid, strong base, or weak base, and then answer the following  question. Suppose 0.0139 g of HNO3 is dissolved in 625 mL of aqueous solution. What is the pH?   a. 1.65 b. 3.66 c. 6.45 d. 3.45 e. 4.65

What is the charge of Cr in the complex [Cr(CN)2(NO2)2]- ? a. +5 b. 0 c. +3 d. +1 e. -1   Tables.pdf Periodic Table with New Elements.pdf

Which of the following compound(s) is (are) ionic? 1. BaBr2          2. Fe2(CO3)3        3. Sr(OH)2         4. SO2   5. C6H12O6   a. 1 and 2 only b. 1, 2, and 3 only c. 4 and 5 only d. 1, 2, 3, and 4 only e.  All are ionic

What is the solubility of BiI3 (s) (in g/L) in a solution that contains 0.90 M I- (aq)? a. 1.1 x 10-18 g/L b. 2.4 x 10-17 g/L c. 5.3 x 10-16 g/L d. 1.8 x 10-16 g/L  e. 6.6 x 10-16 g/L    Tables.pdf Periodic Table with New Elements.pdf