Final answer:
Adding Cr(OH)3 to NaOH results in an acid-base neutralization reaction, with no precipitation, redox reaction, or gas evolution occurring.
Step-by-step explanation:
When Cr(OH)3 is added to NaOH, an acid-base reaction occurs, specifically a reaction between a weak acid and a strong base. Chromium hydroxide, Cr(OH)3, is a weak acid, and sodium hydroxide, NaOH, is a strong base. In this reaction, Cr(OH)3 does not form a precipitate nor does it participate in a redox reaction. Neither does it evolve a gas as no gas-forming reactants or conditions are present. Therefore, the correct answer is option C, Acid-base neutralization. This is because the hydroxide ions (OH-) from the NaOH will react with the Cr(OH)3, perhaps to form a complex ion or simply dissolve the Cr(OH)3 if the concentration is high enough.
.