Question

2C8H18 + 25O2 - 16CO2 + 18 H2O 1)how many moles of co2 are produced when one mole of octane burns 2)what volume at stp is occupied by the number of moles found above 3)if the relative molecular mass of co2 is 44 what is the mass of co2 produced by burning two moles of octane

Answer 1

Dear Student,

$$\begin{gathered} 2{\mathrm{C}}_8{\mathrm{H}}_{18}+25{\mathrm{O}}_2\to 16{\mathrm{CO}}_2+18{\mathrm{H}}_2\mathrm{O} \\ 2\mathrm{mol}16\mathrm{mol} \\ 1)2\mathrm{mol}\mathrm{of}\mathrm{octane}\mathrm{gives}16\mathrm{mol}\mathrm{of}{\mathrm{CO}}_2 \\ \mathrm{Therefore},1\mathrm{mol}\mathrm{of}\mathrm{octane}\mathrm{gives}\frac{16}{2}\times 1=8\mathrm{mol}\mathrm{of}{\mathrm{CO}}_2 \\ 2)\mathrm{At}\mathrm{STP},1\mathrm{mol}=22.4\mathrm{L} \\ \mathrm{Therefore},8\mathrm{mol}\mathrm{of}{\mathrm{CO}}_2=22.4\times 8=179.2\mathrm{L} \\ 3)2\mathrm{moles}\mathrm{of}\mathrm{octane}\mathrm{gives}16\mathrm{mol}\mathrm{of}{\mathrm{CO}}_2 \\ \mathrm{Number}\mathrm{of}\mathrm{moles}=\frac{\mathrm{Mass}}{\mathrm{Molecular}\mathrm{mass}} \\ \mathrm{If}\mathrm{molecular}\mathrm{mass}=44\mathrm{u} \\ \mathrm{Therefore},\mathrm{mass}\mathrm{of}{\mathrm{CO}}_2\mathrm{produced}=16\times 44=704\mathrm{u}\mathrm{of}{\mathrm{CO}}_2\mathrm{is}\mathrm{produced} \end{gathered}$$