The decomposition temperature is maximum for:-

Options

A. `BeCO_(3)`
B. `CaCO_(3)`
C. `K_(2)CO_(3)`
D. `Li_(2)CO_(3)`

Answer

To determine which compound has the maximum decomposition temperature among the given options (Lithium, Beryllium, Potassium, and Calcium), we can follow these steps:

### Step 1: Understand the Concept of Decomposition Temperature
Decomposition temperature refers to the temperature at which a compound breaks down into simpler substances. Generally, the stability of a compound affects its decomposition temperature.

### Step 2: Identify the Elements and Their Compounds
We are given four elements: Lithium (Li), Beryllium (Be), Potassium (K), and Calcium (Ca). We need to consider their respective carbonates for comparison:
- Lithium carbonate (Li2CO3)
- Beryllium carbonate (BeCO3)
- Potassium carbonate (K2CO3)
- Calcium carbonate (CaCO3)

### Step 3: Analyze the Trends in Decomposition Temperatures
1. **Group Trends**: As we move down a group in the periodic table, the stability of the carbonates generally decreases, leading to lower decomposition temperatures.
2. **Period Trends**: As we move across a period from left to right, the decomposition temperature tends to increase due to increased ionic character and stability of the compounds.

### Step 4: Compare the Decomposition Temperatures
- **Lithium Carbonate (Li2CO3)**: Has a relatively high decomposition temperature due to the small size and high charge density of lithium.
- **Beryllium Carbonate (BeCO3)**: Decomposes at a lower temperature compared to lithium carbonate.
- **Potassium Carbonate (K2CO3)**: Has a lower decomposition temperature than lithium carbonate due to the larger size of potassium.
- **Calcium Carbonate (CaCO3)**: Decomposes at a moderate temperature, but still lower than lithium carbonate.

### Step 5: Conclusion
Among the carbonates of the given elements, **Lithium Carbonate (Li2CO3)** has the highest decomposition temperature, followed by Beryllium, then Calcium, and finally Potassium. Therefore, the compound with the maximum decomposition temperature is **Lithium Carbonate (Li2CO3)**.

### Final Answer
The decomposition temperature is maximum for **Lithium Carbonate (Li2CO3)**.

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