Question

Assuming that petrol is octane $C_8{H}_{1}8$ and has density 0.8 g/ml, 1.425 litre of petrol on complete combustion will consume

• A. 50 mole of O₂
• B. 100 mole of O₂
• C. 125 mole of O₂
• D. 200 mole of O₂

Answer 1

The correct option is C

125 mole of O₂

$m_{octane}$=d$\times$v

=0.8$\times$1425

=1140gm

$n_{octane}$ =$\frac{1140}{114}$=10 moles

$C_{18}{H}_{18}$+$\frac{25}{2}{O}_2$$⟶$$8C{O}_2$+9$H_{2}O$

For 1 mole of octane 12.5 moles of oxygen is required so for 10 moles of octane 125 moles of oxygen is required.