Under adiabatic conditions, all the heat released by the polymerization stays in the material, so it heats up rather than losing energy to the surroundings. The heat released per kilogram is 1000 kJ/kg (the magnitude of the heat of polymerization). The temperature rise is the heat added per kilogram divided by the material’s heat capacity per kilogram: DeltaT = q/Cp = 1000 kJ/kg / 2 kJ/kg-K = 500 K. Starting from 200 K, the maximum adiabatic temperature the material could reach is 200 K + 500 K = 700 K. The result shows a final temperature of 700 K; the option with a negative sign would imply cooling, which isn’t consistent with an exothermic, adiabatic heat release.

Venting or pressure relief is needed whenever gas generation or heat from a process could raise the system pressure to dangerous levels, creating a risk of equipment failure or release of hazardous contents. A safe release path exists to relieve that buildup in a controlled way, protecting people and equipment. This is precisely what the correct scenario describes: potential overpressure due to gas generation or heat and the need for a controlled vent to prevent a dangerous rise in pressure. If a reaction is merely exothermic but the pressure stays within the vessel’s design limits, venting isn’t automatically required. Visual cues like product appearance don’t address pressure risks, so they don’t justify venting. And if pressure is already decreasing on its own, there’s no need for a relief path. In practice, engineers assess the potential gas generation and heat to determine whether and how much relief capacity is needed to keep pressure within safe bounds.

Monitoring process pressure requires a device that directly senses pressure and converts it into a usable signal for readings or control. A pressure sensor does exactly that: it detects the actual pressure in a vessel or line and outputs an electrical signal that can be read by displays or fed into a control system for monitoring and safety actions. The temperature indicator, by contrast, measures temperature, not pressure. The Basic Process Control System is the overall system that processes sensor signals and controls equipment, not a single device that directly measures pressure. CRW isn’t a standard pressure-monitoring device in typical process safety contexts. So, the pressure sensor is the correct choice because it provides the actual pressure measurement needed to monitor the process.

Reactivity hazards arise when incompatible chemicals come into contact and react, potentially releasing heat, gas, or pressure. Accidental mixing of incompatible substances is the scenario most likely to trigger such a hazard because it creates the first opportunity for a violent or uncontrolled chemical reaction. When substances that shouldn’t react with each other do mix, the resulting reaction can escalate quickly, leading to overheating, gas buildup, pressure rise, fire, or even an explosion. That risk is inherent to the reaction itself, not to a safety measure being applied. The other scenarios describe safety practices that reduce or prevent hazards. Storing chemicals properly and venting helps prevent build-up of dangerous vapors and moisture-related issues. Using an inert atmosphere with appropriate controls stops reactions with air or moisture. Maintaining proper temperature and pressure reduces the chance of a runaway reaction. None of these, by themselves, describe an immediate hazard—rather, they are ways to keep hazards from occurring.