Phosphine is prepared in the laboratory by the reaction of

Options

A. P and `H_(2)SO_(4)`
B. P and NaOH
C. P and `H_(2)S`
D. P and `HNO_(3)`

Explanation

To prepare phosphine (PH₃) in the laboratory, we can follow these steps:

### Step 1: Understand the Reactants
Phosphine is prepared by reacting phosphorus (P₄) with sodium hydroxide (NaOH) and water (H₂O). It's important to know that phosphorus can exist in several allotropes, with white phosphorus (P₄) being commonly used in laboratory preparations.

**Hint:** Identify the key reactants involved in the reaction to form phosphine.

### Step 2: Write the Reaction
The reaction can be represented as follows:
\[ P_4 + 4 NaOH + 2 H_2O \rightarrow 2 PH_3 + 2 NaH_2PO_2 \]
In this reaction, phosphorus reacts with sodium hydroxide and water to produce phosphine and sodium hypophosphite (NaH₂PO₂).

**Hint:** Write down the balanced chemical equation to understand the stoichiometry of the reaction.

### Step 3: Conduct the Reaction
In the laboratory, the reaction is typically carried out by mixing white phosphorus with a concentrated solution of sodium hydroxide and water. The mixture is heated under controlled conditions to facilitate the reaction.

**Hint:** Consider the physical conditions (like heating) that may be necessary for the reaction to proceed effectively.

### Step 4: Collect the Phosphine
As phosphine is formed, it can be collected by displacement of air or by using a gas jar. Since phosphine is lighter than air, it will rise and can be captured at the top of the jar.

**Hint:** Think about how gases can be collected in laboratory settings.

### Step 5: Purify the Phosphine
The phosphine produced may contain impurities, so it may need to be purified. This can be done by passing it through a drying agent or by other methods to remove any unreacted materials or by-products.

**Hint:** Consider methods of purification commonly used in chemistry to ensure the product is of high purity.

### Final Summary
The laboratory preparation of phosphine involves the reaction of phosphorus (P₄) with sodium hydroxide and water, resulting in the formation of phosphine (PH₃) and sodium hypophosphite (NaH₂PO₂). The reaction requires careful handling and collection methods to ensure the successful production of phosphine.