The enthalpy change for chemical reaction is denoted aas `DeltaH^(Theta)` and `DeltaH^(Theta) = H_(P)^(Theta) - H_(R)^(Theta)`. The relation between enthalpy and internal energy is expressed by equation:
`DeltaH = DeltaU +DeltanRT`
where `DeltaU =` change in internal energy `Deltan =` change in number of moles, `R =` gas constant.
Which of the following equations corresponds to the definition of enthalpy of formation at `298K`?

Options

A. `C("graphite") +2H_(2)(g) +1//2O_(2)(l) rarr CH_(3)OH(g)`
B. `C("diamond")+2H_(2)(g) +1//2O_(2)(g)rarr CH_(3)OH(l)`
C. `2C("graphite")+4H_(2)(g) +O_(2)(g) rarr 2CH_(3)OH(l)`
D. `C("graphite") +2H_(2)(g)+1//2O_(2)(g) rarr CH_(3)OH(l)`

Explanation

To solve the question regarding the enthalpy of formation at 298 K, we need to follow these steps:

### Step 1: Understand the Definition of Enthalpy of Formation
The enthalpy of formation is defined as the heat energy released or absorbed when one mole of a compound is formed from its constituent elements in their standard states at a specified temperature, typically 298 K.

### Step 2: Identify the Standard States of Elements
For the enthalpy of formation, we need to ensure that the elements involved are in their standard states:
- Carbon (C) in its standard state is graphite.
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