Consider these two entries from a fictional table of standard reduction potentials: A: X^{2+} + 2e^- → X(s)E^\(\text{°}\) = -0.50 V B: Y^{+} + e^- → Y(s)E^\(\text{°}\) = +0.30 V Which species is the stronger oxidizing agent under standard conditions?

What is the oxidation number of each underlined element?

a) P₄                                  b) BO₃^3–                                c) AsO₄^2–                           d) HSO₄^–

In the following reaction identify the oxidizing agent and the reducing agent:

Cr₂O₇^2- + 6 Fe²⁺ + 14 H⁺ → 2 Cr³⁺ + 6 Fe³⁺ + 7 H₂O

3 Pb²+ (aq) + 2 Cr (s) → 3 Pb (s) + 2 Cr³⁺ (aq)