Calorimetry Quiz

Which of the following best explains why steam at 100°C causes more severe burns than boiling water at 100°C?

1. Steam has a higher temperature than boiling water
2. Steam has more latent heat than boiling water
3. Steam has a lower density than water
4. Water evaporates quickly, reducing heat transfer

Answer: (b) Steam has more latent heat than boiling water

If water is used to cool a metal piece and the metal has a much lower specific heat capacity than water, which of the following is the most likely consequence?

1. The metal and water will not exchange heat.
2. The metal will cool slowly, and the water will heat up rapidly.
3. Both the metal and water will cool at the same rate.
4. The metal will cool quickly, but the water will heat up slowly.

Answer: (d) The metal will cool quickly, but the water will heat up slowly.

A student condenses steam at 100°C and measures the temperature change as heat is released. The graph shows a flat region at 100°C. What does this indicate?

1. Steam releases latent heat before its temperature decreases
2. Steam cools down first, then condenses
3. The rate of condensation is decreasing
4. The temperature of steam increases before condensation.

Answer: (a) Steam releases latent heat before its temperature decreases

If a substance has a high latent heat of vaporization, what can be inferred about its phase change from liquid to gas?

1. It will evaporate easily at room temperature.
2. It will freeze at lower temperatures.
3. Its boiling point will be lower than substances with lower latent heat.
4. It requires a significant amount of heat energy to vaporize.

Answer: (d) It requires a significant amount of heat energy to vaporize.

A student performs an experiment to determine the latent heat of fusion of ice by mixing ice at 0°C with water at 80°C in an insulated calorimeter. However, the student notices the final water temperature is lower than expected. What could be a valid explanation?

1. The calorimeter absorbed some heat
2. The specific heat of ice is greater than that of water
3. Some of the ice was at -10°C instead of 0°C
4. The student miscalculated the heat lost by water

Answer: (c) Some of the ice was at -10°C instead of 0°C

Two liquids, A and B, of the same mass, are placed in a room for cooling. Their cooling curves are shown in a graph. Which of the following statements correctly describes A and B?

1. Both A and B have the same freezing point
2. A has a higher specific latent heat of fusion than B
3. B freezes before A
4. A cools faster than B

Answer: (a) Both A and B have the same freezing point

A student heats two different substances, A and B, and plots temperature vs. heat supplied. Substance A remains at 0°C longer than B. What does this indicate?

1. A has a higher latent heat of fusion than B
2. Substance B has a higher latent heat of fusion than A.
3. A has a lower melting point than B
4. Both A and B have the same specific heat capacity

Answer: (b) Substance B has a higher latent heat of fusion than A.

A student mixes 100 g of water at 60°C with 100 g of ice at 0°C. The final equilibrium temperature is 10°C. Calculate the heat required to melt the ice and bring it to the final temperature, assuming the latent heat of fusion of ice is 300 J/g and the specific heat capacity of water is 4 J/g°C.

1. 21,000 J
2. 24,000 J
3. 32,000 J
4. 34,000 J

Answer: (d) 34,000 J

A calorimeter contains 200 g of water at 20°C. If a 100 g metal block at 80°C is dropped into the water, and the final temperature of the system becomes 25°C, what is the specific heat capacity of the metal? Specific heat capacity of water = 4.18 J/g°C

1. 0.45 J/g°C
2. 0.60 J/g°C
3. 0.76 J/g°C
4. 0.88 J/g°C

Answer: (c) 0.76 J/g°C

Which of the following statements correctly describes the two liquids?

1. Both X and Y freeze at the same temperature
2. X has a higher specific latent heat of fusion than Y
3. Y has a higher specific latent heat of fusion than X
4. Y has a lower freezing point than X

Answer: (b) X has a higher specific latent heat of fusion than Y