Methanol `(CH_(3)OH)` is manufactured by reaction of carbon monoxide with hydrogen in the presence of `ZnO //Cr_(2)O_(3)` catalyst.
`CO+2H_(2(g)),[DeltaH^(@)=-91KJ`]
What happens to the amount of methanol when an equilibrium mixture of reactants and products is subjected to rise in temperature?

Options

A. Amount of methanol will increase
B. Amount of methanol will decrease
C. Amount of methanol remain the same
D. None of these

Answer

To solve the problem regarding the effect of temperature on the equilibrium of the methanol production reaction, we can follow these steps:

### Step 1: Identify the Reaction
The reaction for the production of methanol is:
\[ \text{CO} + 2\text{H}_2 \rightleftharpoons \text{CH}_3\text{OH} \]
This reaction is exothermic, as indicated by the negative enthalpy change (\( \Delta H = -91 \, \text{kJ} \)).

### Step 2: Understand the Nature of the Reaction
Since the reaction is exothermic, it releases heat when moving from reactants to products. Therefore, we can represent the reaction with heat as a product:
\[ \text{CO} + 2\text{H}_2 \rightleftharpoons \text{CH}_3\text{OH} + \text{heat} \]

### Step 3: Apply Le Chatelier's Principle
Le Chatelier's Principle states that if a system at equilibrium is subjected to a change in conditions (such as temperature, pressure, or concentration), the system will adjust to counteract that change and restore a new equilibrium.

### Step 4: Analyze the Effect of Increasing Temperature
When the temperature of the system is increased, the equilibrium will shift in the direction that absorbs heat to counteract the increase in temperature. In this case, since the forward reaction is exothermic (releases heat), increasing the temperature will shift the equilibrium towards the reactants (the endothermic direction).

### Step 5: Conclusion
As a result of the shift towards the reactants, the amount of methanol (\( \text{CH}_3\text{OH} \)) will decrease when the temperature is increased.

### Final Answer
When an equilibrium mixture of reactants and products is subjected to a rise in temperature, the amount of methanol will **decrease**.

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