1 gram of CO₂ is produced by burning 3/11 gram of carbon, the equivalent weight of carbon is

$$\begin{gathered} \mathrm{C} +{\mathrm{O}}_2\to {\mathrm{CO}}_2 \\ 12 \mathrm{gms} 44\mathrm{gms} \\ \mathrm{X} \mathrm{gms} 1 \mathrm{gm} \end{gathered}$$

$\mathrm{X} = \frac{12}{44} =\frac{3}{11}\mathrm{g}$

Change in valency of carbon = 4

E w of carbon = $\frac{\mathrm{A} \mathrm{wt}}{4}=\frac{12}{4}=3$