Question

Assuming that petrol is octane `(C_(8)H_(18))` and has density `0.8 g//ml, 1.425 litre` of petrol on complete combustion will consume
A. (a)`50` mole of `O_(2)`
B. (b)`125` mole of `O_(2)`
C. (c )`100` mole of `O_(2)`
D. (d)`200` mole of `O_(2)`

Answer 1

Correct Answer - b
Mass of octane `=1.425xx103xx0.8 g`
Moles of octane `=(1425xx.8)/114=10` moles
`C_(8)H_(18)+25/2 O_(2) rarr 8CO_(2)+9H_(2)O`
From the equation it can be seen
For 1 mole octane oxygen required `25/2` moles
`:.` For 10 moles octane required `25/2xx10=125` moles