Which equation represents the reaction of a weak acid with water? a. hcl + h2o h3o+ + cl- b. hco3– + h2o h2co3 + oh– c. h2o h + + oh- d. hcooh + h2o h3o+ + hcoo-

Acid is anything which will give H+ to other species.

Have a look at the equations given.

In A) HCl changes to Cl- by giving its H+ to H2O. So HCl is an acid.

In B) HCO3- changes to H2CO3^2- by accepting H+. It did Not give its H+ rather it takes from other species. So it is not an acid at all.

In C) H2O is just breaking to H+ and OH-. It is not giving H+ to other species. So it is also not an acid in this reaction.

In D) HCOOH is giving its H+ to H2O. So it is also an acid.

So out of all reactions with water. The only two species are acting as acid with water namely HCl and HCOOH.

Out of these two HCl is very strong acid but HCOOH is a weak acid.

So the answer is D