d
\({{C}_{x}}{{H}_{y}}\,+\,\,\left( x\,\,+\,\,\frac{y}{4} \right)\,{{O}_{2}}\,\to \,xC{{O}_{2}}_{(g)}\,+\,\,\frac{y}{2}{{H}_{2}}{{O}_{(\ell )}}\)

\({{H}_{2}}O\,\) ના મોલ \(=\,\,\frac{\text{0}\text{.72}}{\text{18}}\,\,=\,\,0.04;\,\,\,\,C{{O}_{2}}\,\) ના મોલ \(=\,\,\frac{\text{3}\text{.08}}{\text{44}}\,\,=\,\,0.07\)

\(\begin{align}
   \because \,\,\,x\,\,:\,\,\frac{y}{2}\,\,=\,\,0.07\,\,:\,\,0.04 \\ 
  \Rightarrow \,\,x\,\,:\,\,y\,\,=\,\,0.07\,\,:\,\,0.08\,\,\,\Rightarrow \,\,7\,\,:\,\,8 \\ 
\end{align}\)

\(\because \,\,C\) અને \(\text{H}\,\,\) વચ્ચેનો ગુનોતર \(\text{x}\,\,\text{:}\,\,\text{y}\) છે 

\(\therefore \,\,\text{C}\,\,\text{:}\,\,\text{H}\,\,=\,\,\text{7}\,\,\text{:}\,\,\text{8}\)

તેથી હાઈડ્રો કાર્બન નું પ્રમાણ સૂત્ર \({{\text{C}}_{\text{7}}}{{\text{H}}_{\text{8}}}\) થાય છે