Question

For the reaction $C _2 H _5 OH ( l )+3 O _2( g ) \longrightarrow 2 CO _2( g )+3 H _2 O ( l )$ which one is true:

• A. $\Delta H =\Delta E - RT$
• B. $\Delta H =\Delta E + RT$
• C. $\Delta H =\Delta E +2 RT$
• D. $\Delta H =\Delta E -2 RT$

Answer 1

Answer: (A)

We know that $\Delta H=\Delta E+\Delta nRT$
where $\Delta n$ = number of moles of gaseous product - number of moles of gaseous reactant
$= 2 - 3 = - 1$
So, $\Delta H=\Delta E-RT$