PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
Three samples, each containing the same amount of substance and initially at 20 °C, are placed separately into a large, well-stirred oven maintained at 80 °C. The samples are:
• a solid copper cube,
• a liquid ethanol sample in a thin-walled glass flask (no evaporation occurs),
• nitrogen gas confined in a rigid steel cylinder.
The dimensions of the containers are such that each sample is exposed to the same external surface area at the oven temperature.
(a) Predict the order (from fastest to slowest) in which the three samples will reach 50 °C. Clearly state your ranking.
(b) Justify your ranking in part (a) by comparing the frequency and effectiveness of molecular collisions that transfer energy from the hot oven environment to each sample.
(c) Suppose you remove each sample from the oven once it has returned to 20 °C and immediately touch its exterior surface. Rank the three samples from “feels coldest” to “feels warmest,” and explain your reasoning in terms of energy transfer properties.