Mole Concept And Molar Masses

To solve this question, we need to determine which option corresponds to the highest mass of water (H₂O).

1. One Mole of H₂O:
A mole of any substance contains particles (Avogadro's number). The molar mass of water (H₂O) is 18 grams per mole. Therefore, one mole of water has a mass of 18 grams.

2. Evaluating Other Options:

• (A) One molecule of H₂O – The mass of a single molecule is very tiny, approximately grams, which is extremely small.
• (B) One gram of H₂O – This corresponds to a mass of 1 gram, which is less than a mole of H₂O.
• (C) One ml of H₂O – One ml of water weighs approximately 1 gram, which is still much less than a mole of water.
• (D) One mole of H₂O – Correct; one mole of H₂O has the highest mass (18 grams).

Final Answer:
The correct answer is (D) One mole H₂O.

To solve the problem, we need to calculate the heat liberated by the combustion of 11.2 liters of propane (C₃H₈) at STP, given that the heat released by one mole of propane is kilojoules.

1. Understanding the Relationship:
At STP (Standard Temperature and Pressure), 1 mole of any ideal gas occupies 22.4 liters. So, the volume of 1 mole of propane (C₃H₈) is 22.4 liters at STP.

2. Given:
- Heat released by 1 mole of propane = kilojoules.
- Volume of 1 mole of propane at STP = 22.4 liters.
- Volume of propane given = 11.2 liters.

3. Using the Proportionality:
The heat released is proportional to the volume of propane. Since 22.4 liters of propane release kilojoules of heat, 11.2 liters (which is half the volume of 22.4 liters) will release half the heat. Therefore, the heat released by the combustion of 11.2 liters of propane is:

Final Answer:
The heat liberated by the combustion of 11.2 liters of propane at STP is kilojoules.