Question

When H2 and CO2 react, acetic acid can be formed spontaneously while the production of formaldehyde requires an input of energy.

Which of the following conclusions may be drawn from this observation?
A) The mineral catalyst involved in acetic acid production provides energy to make the reaction spontaneous.
B) More heat is released when formaldehyde is produced compared to the production of acetic acid.
C) Entropy decreases when acetic acid is produced and increases when formaldehyde is produced.
D) Compared to the reactants from which it is formed, formaldehyde has more potential energy than does acetic acid.

Answer 1

D) Compared to the reactants from which it is formed, formaldehyde has more potential energy than does acetic acid.

Step-by-step explanation:

A reaction ocurrs spontaneously meanly in two cases, when reaction release energy (exothermic reaction) or when the entropy of the system increases.

Option A is false because if reaction needs a catalyst, this reaction in not spontaneous and catalyst don´t provide energy to reaction, only gives a hand to it ocurrs.

In opton B when formaldehyde is produced reaction release heat, so this is the spontaneous reaction, contrary to what was observed.

In option C entropy increases when formaldehyde is produced, also in this case is the spontaneous reaction, contrary to what was observed.

But in option D potential energy of acetic acid is smaller than reactants, it means that energy is release as a heat and reaction ocurrs spontaneously.

By the other hand potential energy of formaldehyde is higher than reactants and needs energy to ocurrs.