Quiz 7 Name: _______________________________________ Chemistry 102, Lecture 401 – Fall 2015 DS Section: (1 point) ____________________________ 1. What are the oxidation numbers of all elements in each of the substances listed? (3 points) a. SO2 S +4 O −2 S +4 b. H2SO3 H + O −2 c. S8 S 0 2. From the list of metals to the right, what is one that will react with hydrochloric acid? (4 points) Al or Sn Al Ag Pt Sn a. Give the balanced equations as noted for this reaction: molecular equation: 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g) Sn(s) + 2HCl(aq) → SnCl2(aq) + H2(g) oxidation half reaction: Al → Al3+(aq) + 3e− Sn → Sn2+(aq) + 2e− reduction half reaction: 2e− + 2H+(aq) → H2(g) 2e− + 2H+(aq) → H2(g) net equation ionic: 6H+(aq) + 2Al(s) → 2Al3+(aq) + 3H2(g) oxidizing agent: HCl 2H+(aq) + Sn(s) → Sn2+(aq) + H2(g) reducing agent: Al or Sn 3. Fill in the blank (2 point): a. A stronger oxidizing agent than HCl Cu2+, Ag+, Hg2+, Pt2+ or Au3+ b. A stronger oxidizing agent than Br2 F2 or Cl2 c. What is one metal that will react with Cr(NO3)3 but will not react with Mg(NO3)2? aluminum or zinc 4. Complete the table. (3 points) Solution Molar mass [AlCl3] Mass of AuCl3 Solution Vol [Cl−] AuCl3 303.35 g∙mol−1 0.00833 M 0.190 g 75.00 mL 0.0250 M Work: ⎛ 0.0250 mol Cl− ⎞ ⎛ 1 mol AuCl3 ⎞
= 0.00833 M AuCl3
⎜
⎟⎜
− ⎟
L
⎝
⎠ ⎝ 3 mol Cl ⎠
⎛ 303.35 g AuCl3 ⎞
⎛ 0.00833 mol AuCl3 ⎞
( 0.07500 L ) ⎜
⎟ = 0.190 g AuCl3
⎜
⎟
L
⎝
⎠
⎝ mol AuCl3 ⎠