d
\(\begin{gathered}
  {{\text{C}}_{\text{x}}}{H_y}\, + \,\left[ {\frac{{4x + y}}{4}} \right]\,\,{O_2}\,\, \to \,\,\,xC{O_2}\,\, + \,\frac{y}{2}{H_2}O(\ell ) \hfill \\
  \,\,\,\,\,\,\,\,\,\,500\,ml\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,500\,x\,\,\,\,\,\,\,\,\,500 \times \frac{y}{2}\, \hfill \\
  500x = 2.5 \times {10^3}ml\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,500 \times \frac{y}{2}\,\,\, = \,\,\,3 \times {10^3} \hfill \\
  x = 5\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,y = 12\,\,\,\,\,\,\,\,\,\,\,{C_5}{H_{12}}\,\,\, \hfill \\ 
\end{gathered} \)