Chemistry Regents Practice Test

In a laboratory where the air temperature is 22°C, a steel cylinder at 100.°C is submerged in a sample of water at 40.°C. In this system, heat flows from?

1. The cylinder to the water

2. The water to the cylinder

3. The cylinder to the air

4. The water to the air

The correct answer is: The cylinder to the water

Heat transfer occurs from a hotter object to a cooler object until thermal equilibrium is reached. In this scenario, the steel cylinder is at 100°C, while the water is at 40°C. Since the temperature of the cylinder is significantly higher than that of the water, heat flows from the cylinder to the water. This transfer of heat will continue until the temperatures of the two are closer together, ultimately resulting in the water gaining heat and the cylinder losing heat. The other options do not accurately reflect this principle of heat transfer. The water cannot transfer heat to the cylinder since it is at a lower temperature. Similarly, the cylinder cannot transfer heat to the air since the air is at a lower temperature than the cylinder, and the water does not transfer heat to the air in this context, as it is a separate scenario involving the warmer water and cooler air. Thus, the correct answer represents the natural direction of heat flow, following the fundamental laws of thermodynamics.