Question

Rice takes about 10 minutes to boil on Earth in open conditions. If the same experiment is performed on Mars, what will happen?

• A. Rice will boil in the same time
• B. Rice will boil faster
• C. Rice will take more time to boil
• D. Rice will not boil properly

Hint:

This is an extreme version of the "cooking on a mountain" problem (Q-14). The key takeaway is that "boiling" does not always mean "hot." Boiling is a pressure-dependent phenomenon, while cooking is a temperature-dependent chemical reaction. On Mars, the pressure is so low that water boils before it can get hot enough to cook food.

Answer 1

The Correct Option is D

Step 1: Understanding the Question: The question compares the process of cooking rice in boiling water on Earth versus on Mars. This requires knowledge of the atmospheric conditions on Mars and their effect on the boiling point of water.

Step 2: Key Concepts:
• Boiling Point: Water boils when its vapor pressure equals the surrounding atmospheric pressure.
• Atmospheric Pressure on Mars: Mars has an extremely thin atmosphere. Its surface pressure is, on average, about 600 Pascals, which is less than 1% of Earth's sea-level pressure of 101,325 Pascals.
• Cooking: Cooking is a chemical process that requires a certain minimum temperature to proceed effectively. For rice, this involves the gelatinization of starch, which needs temperatures well above room temperature.

Step 3: Detailed Explanation: Due to the extremely low atmospheric pressure on Mars, the boiling point of water is drastically reduced. Water on Mars would boil at a temperature just above its freezing point, approximately between 0°C and 10°C, depending on the exact location and time. While the water would technically "boil" (i.e., undergo a rapid phase transition to vapor), the temperature at which this happens is far too low to cook the rice. The chemical reactions required to soften the rice grains and make them edible would not occur at such a low temperature. The water would simply boil away, leaving behind uncooked, wet rice.

Step 4: Final Answer: The water would boil at a very low temperature, insufficient for cooking. Therefore, the rice will not boil properly.