The following reaction does not proceed to a product: h2o + au - no reaction.
why is that?

a) gold has a lower activity than hydrogen and cannot replace it.

b) gold has a higher activity than hydrogen and cannot replace it.

c) the reaction cannot occur because water is a reactant.

For the given reaction, gold has a lower activity than hydrogen and cannot replace it.

Explanation:

Single-displacement reactions are defined as the reactions in which a more reactive metal displaces a less reactive metal from its chemical reaction. The reactivity of metal is judged by a series known as reactivity series.

Metal A is more reactive than metal B.

The metal which is present above in the series is more reactive than the metal which is present below in the series.

For the given chemical reaction:

In the above reaction, gold lies low in the reactivity series than hydrogen and so, it cannot replace hydrogen from the chemical reaction and thus, no reaction occurs.

Hence, for the given reaction, gold has a lower activity than hydrogen and cannot replace it.