A compound of Zinc which is white in cold state and yellow in hot state, is

Options

A. `ZnS`
B. `ZnO`
C. `ZnCl_(2)`
D. `ZnZO_(4)`

Explanation

To solve the question regarding the compound of zinc that is white in the cold state and yellow in the hot state, we can follow these steps:

### Step 1: Identify the Compound
We need to identify a compound of zinc that exhibits a color change with temperature. The question specifies that the compound is white when cold and yellow when hot.

### Step 2: Analyze the Options
The options provided are:
1. ZnS
2. ZnO
3. ZnCl2
4. ZnZO4

### Step 3: Recall the Properties of ZnO
Zinc oxide (ZnO) is known to exhibit a color change with temperature. At lower temperatures, ZnO appears white, and when heated, it can appear yellow due to the formation of non-stoichiometric zinc oxide or defects in the crystal lattice.

### Step 4: Confirm the Color Change
When ZnO is heated, it can lose some oxygen and form a non-stoichiometric compound, which gives it a yellow color. Therefore, it fits the description given in the question.

### Step 5: Conclusion
Based on the analysis, the compound of zinc that is white in the cold state and yellow in the hot state is **ZnO**.

### Final Answer
The compound of Zinc which is white in cold state and yellow in hot state is **ZnO**.

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