Step 1: Understanding the Concept
For a reaction at constant temperature and pressure, work done on the system is \(w=-\Delta n_g RT\), where \(\Delta n_g\) is the change in moles of gas.
Step 2: Write the reaction
\(\text{C(s)}+2\text{H}_{2}\text{(g)}\rightarrow\text{CH}_{4}\text{(g)}\)
\(\Delta n_g=1-2=-1\).
Step 3: Calculation
\(T=27+273=300\) K.
\(w=-(-1)\times8.314\times300=+2494.2\) J \(=+2.4942\) kJ.
Final Answer:
The work done is \(+2.4942\) kJ.
\[ \boxed{\text{(B) }+2.4942\ \text{kJ}} \]