A student performs a multi-step laboratory sequence that converts ferrous sulfate…
CHEMISTRY · Multi-part · AP · Chemistry · Chemical Reactions · Chemical Reactions
Problem
A student performs a multi-step laboratory sequence that converts ferrous sulfate into solid iron(III) oxide.
Step 1: FeSO4(aq) is treated with an acidic solution of H2O2(aq).
Step 2: Excess NaOH(aq) is added to the resulting solution, forming a gelatinous brown precipitate.
Step 3: The precipitate is filtered, dried, and strongly heated to yield a reddish solid and water vapor.
(a) Write the balanced molecular equation for the reaction that occurs in Step 1 and classify the reaction. Justify your classification with reference to electron transfer and to oxidation-number changes.
(b) Write the balanced net-ionic equation for Step 2. Classify this step and explain the principal driving force that favors product formation.
(c) The dehydration that takes place in Step 3 produces Fe2O3(s). Discuss whether any redox process occurs in this step and classify the reaction accordingly.
(d) Compare and contrast the exchanges of electrons, protons, and ions that occur across the three steps. Explain how the overall sequence illustrates the interplay among different reaction classes while accomplishing a single synthetic goal.