One mole of ethanol when burnt in oxygen, gives out a: kJ mol-1 heat. If one mole of O2 is used, what will be the amount of heat evolved?

Question

One mole of ethanol when burnt in oxygen, gives out a: kJ mol-1 heat. If one mole of O2 is used, what will be the amount of heat evolved? (A)  x kJ  (B)  (x/3) kJ  (C)  3x kJ  (D)  (3x/2) kJ

Tardigrade Admin · Accepted Answer

C2H5OH+3O2 xrightarrow2CO2+3H2O;Δ H=-xkJ By burning with 3 moles of O2 heat evolved =-xkJ ∴ by burning with 1 mole of O2 heat evolved =-(x/3)kJ

Q. One mole of ethanol when burnt in oxygen, gives out a: kJ $m o l^{- 1}$ heat. If one mole of $O_{2}$ is used, what will be the amount of heat evolved?

$x k J$

$\frac{x}{3} k J$

$3 x k J$

$\frac{3 x}{2} k J$

$C_{2} H_{5} O H + 3 O_{2} 2 C O_{2} + 3 H_{2} O; Δ H = - x k J$ By burning with 3 moles of $O_{2}$ heat evolved $= - x k J$ $∴$ by burning with 1 mole of $O_{2}$ heat evolved $= - \frac{x}{3} k J$

Q. One mole of ethanol when burnt in oxygen, gives out a: kJ mol−1 heat. If one mole of O2​ is used, what will be the amount of heat evolved?

xkJ

3x​kJ

3xkJ

23x​kJ