Identify the unbalanced half-reaction in which a species is reduced. O C(s) CO(g) O Al(s) Al3+(aq) - O 21(aq) I,(s) O Cr,0,(s) CrO?"(aq) O so (aq) H,S(g)

Balance the following half-reactions by adding the appropriate number of electrons (e-). Then, classify each reaction as an oxidation or reduction half-reaction. Note that for each of the four reactions, one of the gray boxes will be left blank and the other will be filled with electron(s). Use the symbol e- to represent an electron. Part 4 + 12(s) + 6H2O(1) > 2I0-3 + 12H+(aq) + --

A certain metal è forms a soluble sulfate salt ₂(so). Suppose the left half cell of a galvanic cell apparatus is filled with a 5.00 M solution of M₂(SO4)3 and the right half cell with a 250. mM solution of the same substance. Electrodes made of M are dipped into both solutions and a voltmeter is connected between them. The temperature of the apparatus is held constant at 35.0 °C. Which electrode will be positive? O left Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits. O right What voltage will the voltmeter show? Assume its positive lead is connected to the positive electrode. 0 x10 X

q19

Balance the below unbalanced redox reaction in acidic media. In the balanced redox reaction, there are ( Select ] water molecules in the reactants and [: [ Select ] AIO2 ions in the products. NO2 (aq) + Al (s) → NH4* (aq) + AIO2 (aq)

(19) Consider the following redox reaction that occurs in a voltaic cell: Cr2+ (aq) + Cu²+ (aq) → Cr³+ (aq) + Cut (aq) If the cell is operating at 25°C, what is the value of the equilibrium constant (Keq)? (A) 1.41 x 10¹1 1.19 x 1018 5.53 x 105 2.79 x 1033 1.81 x 10-6 (B) (C) (D) (E)