Question 56

The Correct Answer is B. --- ### 2. Explanation of Why Option B is Correct **B) Propylene oxide may not be stowed in a tank adjacent to butyric acid.** Propylene Oxide belongs to the chemical group known as Alkylene Oxides (Epoxides). Butyric Acid is a carboxylic acid. Acids react violently with Alkylene Oxides, causing a rapid, highly exothermic (heat-producing) reaction that leads to polymerization. This reaction can build up extreme heat and pressure, potentially leading to tank rupture, fire, or explosion if the chemicals mix. Due to this severe chemical incompatibility, regulatory guidelines (such as those found in the IMO IBC Code, Chapter 15, or US Coast Guard regulations) strictly mandate that incompatible chemicals of this nature (like Acids and Alkylene Oxides) **must be separated** by at least one empty tank, a cofferdam, or a pump room. They cannot be stowed in adjacent tanks sharing a common bulkhead. Therefore, this statement is true. --- ### 3. Explanation of Why Other Options are Incorrect **A) Butyric acid is incompatible with octyl alcohol but not propylene oxide.** * **Incorrect:** Butyric acid (an acid) is compatible with Octyl Alcohol (an alcohol) for bulk transport purposes (any reaction would be slow esterification). Crucially, Butyric acid is **highly incompatible** with Propylene Oxide (an epoxide), making the second part of the statement false. **C) Octyl alcohol is incompatible with both butyric acid and propylene oxide.** * **Incorrect:** Octyl alcohol (a typical fatty alcohol) is stable and is compatible with both butyric acid and propylene oxide under normal tanker transport conditions. Alcohols are chemically separated from the highly reactive groups (Acids and Epoxides) on compatibility charts. **D) All of these cargoes are compatible.** * **Incorrect:** As established above, Butyric Acid and Propylene Oxide are highly incompatible and require physical separation.