Question

Which of the following is kept immersed in water ?

• A. White phosphorus
• B. Red phosphorus
• C. Iodine
• D. Sulphur

Hint:

Remember the storage conditions for highly reactive elements. Alkali metals like Sodium (Na) and Potassium (K) are stored under kerosene or paraffin oil because they react violently with water. White Phosphorus reacts with air, not water, so it's stored under water.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Some highly reactive elements need to be stored under specific conditions to prevent them from reacting with the environment (like air).

Step 2: Detailed Explanation:
\[\begin{array}{rl} \bullet & \text{White phosphorus: This allotrope of phosphorus is highly reactive. It has a low ignition temperature (around 30\(^{\circ}\)C) and ignites spontaneously upon exposure to air, burning with a yellow flame to produce dense white fumes of phosphorus pentoxide (\(P_4O_{10}\)). To prevent this, it is stored under water, with which it does not react. } \\ \bullet & \text{Red phosphorus: Is much more stable and less reactive than white phosphorus. It does not ignite in air at room temperature and can be stored normally. } \\ \bullet & \text{Iodine and Sulphur: Are relatively stable solids at room temperature and do not need to be stored under water. } \\ \end{array}\]

Step 3: Final Answer:
White phosphorus is kept immersed in water for safe storage.