Equimolar amounts of `H_(2) and I_(2)` were taken in a bulb maintained at `500 ^(@) C.` Dark violet colour faded to light violet which does not change further. This shows that the bulb contains `…………..` amounts of `…………. . `

Answer

To solve the question step by step, we will analyze the information provided and the chemical reactions involved.

### Step 1: Understand the Initial Conditions
Equimolar amounts of \( H_2 \) (hydrogen) and \( I_2 \) (iodine) are placed in a bulb at a temperature of \( 500^\circ C \).

**Hint:** Remember that "equimolar" means the same number of moles of both substances are present.

### Step 2: Identify the Color Change
Initially, the mixture has a dark violet color, which indicates the presence of \( I_2 \). As the reaction progresses, the color fades to light violet and does not change further.

**Hint:** The color change indicates that a reaction is occurring, and the dark violet color is due to \( I_2 \).

### Step 3: Write the Chemical Reaction
The reaction that occurs between \( H_2 \) and \( I_2 \) is:
\[ H_2(g) + I_2(g) \rightleftharpoons 2 HI(g) \]
This reaction produces hydrogen iodide (\( HI \)), which is colorless, thus contributing to the fading of the violet color.

**Hint:** Recognize that the formation of \( HI \) reduces the concentration of \( I_2 \), leading to the color change.

### Step 4: Establish Equilibrium
The fact that the color does not change further indicates that the system has reached equilibrium. At equilibrium, the concentrations of \( H_2 \), \( I_2 \), and \( HI \) remain constant.

**Hint:** Equilibrium means the forward and reverse reactions occur at the same rate, resulting in stable concentrations.

### Step 5: Determine the Amounts Present
Since the question asks for the amounts present in the bulb, we conclude that the bulb contains fixed amounts of \( H_2 \), \( I_2 \), and \( HI \) at equilibrium.

**Hint:** The term "fixed amounts" suggests that the concentrations of the reactants and products do not change anymore.

### Final Answer
The bulb contains **fixed amounts of** \( H_2 \), \( I_2 \), and \( HI \).

### Summary
To summarize, the bulb contains fixed amounts of \( H_2 \), \( I_2 \), and \( HI \) at equilibrium, as indicated by the stable light violet color.