Question

If \( \mathrm{C(s) + O_2(g) \rightarrow CO_2(g)} \), \( \Delta H = -396 \,\mathrm{kJ\,mol^{-1}} \), calculate heat liberated during formation of 0.154 kg of \( \mathrm{CO_2} \).

• A. 1386.0 kJ
• B. 346.5 kJ
• C. 693.0 kJ
• D. 1039.5 kJ

Hint:

Always convert mass into moles before applying thermochemical data.

Answer 1

The Correct Option is A

Step 1: Calculating moles of CO\(_2\).
\[ \text{Moles} = \frac{154}{44} = 3.5 \]

Step 2: Using enthalpy change.
Heat released per mole of CO\(_2\) = 396 kJ

Step 3: Calculating total heat released.
\[ \text{Total heat} = 3.5 \times 396 = 1386 \, \text{kJ} \]

Step 4: Conclusion.
The heat liberated is 1386.0 kJ.