Low temperature is favourable for ……….. reactions.

Answer

To solve the question "Low temperature is favourable for ……….. reactions," we need to analyze the relationship between temperature and the types of chemical reactions, specifically exothermic and endothermic reactions.

### Step-by-Step Solution:

1. **Identify Reaction Types**:
- There are two main types of reactions based on heat exchange: exothermic and endothermic.
- Exothermic reactions release heat, while endothermic reactions absorb heat.

2. **Understanding Exothermic Reactions**:
- In an exothermic reaction, the reactants (A) transform into products (B) while releasing heat. This can be represented as:
\[ A \rightarrow B + \text{Heat} \]
- When the temperature is lowered, the system will try to counteract this change by shifting the equilibrium to produce more heat, thus favoring the forward reaction.

3. **Understanding Endothermic Reactions**:
- In an endothermic reaction, the reactants absorb heat to form products:
\[ A + \text{Heat} \rightarrow B \]
- If the temperature is increased, the system will absorb more heat, favoring the forward reaction. Conversely, lowering the temperature would hinder the reaction since it requires heat to proceed.

4. **Conclusion**:
- Since exothermic reactions release heat and are favored at lower temperatures (as the system shifts to produce more heat), we conclude that low temperature is favorable for **exothermic reactions**.

### Final Answer:
Low temperature is favorable for **exothermic reactions**.

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