MCQ
If C (diamond $) \rightarrow C$ (graphite $)+ X kJ mol { }^{-1}$$
\begin{array}{l}
C(\text { diamond })+O_2(g) \rightarrow CO_2(g)+Y kJ mol^{-1} \\
C(\text { graphite })+O_2(g) \rightarrow CO_2(g)+ZkJ mol^{-1}
\end{array}
$
At constant temperature. Then
\begin{array}{l}
C(\text { diamond })+O_2(g) \rightarrow CO_2(g)+Y kJ mol^{-1} \\
C(\text { graphite })+O_2(g) \rightarrow CO_2(g)+ZkJ mol^{-1}
\end{array}
$
At constant temperature. Then
- A$X = Y + Z$
- B$-X=Y+Z$
- C$X=-Y+Z$
- ✓$X=Y-Z$