Question

Which compounds yield hydrogen ions as the only positive ions in an aqueous solution?

1) H₂CO₃ and HC₂H₃O₂
2) H₂CO₃ and NaHCO₃
3)NH₃ and HC₂H₃O₂
4) NH₃ and NaHCO₃

Answer 1

The compounds that yield hydrogen ions as the only positive ions in an aqueous solution are acids. Among the choices provided, H₂CO₃ (carbonic acid) and HC₂H₃O₂ (acetic acid) are the correct answers as both of them dissociate in water to produce hydrogen ions. Therefore, option 1 is the correct choice.

Step-by-step explanation:

The compounds that yield hydrogen ions as the only positive ions in an aqueous solution are typically acids. An acid dissociates in water to produce hydrogen ions (H+), or more accurately hydronium ions (H3O+), and an anion. The options given appear to present different combinations of compounds, and we need to identify which of those combinations consist of acids that will yield hydrogen ions in solution.

Looking at the choices:

1. H₂CO₃ (carbonic acid) and HC₂H₃O₂ (acetic acid) both yield hydrogen ions when dissolved in water.
2. H₂CO₃ (carbonic acid) does produce hydrogen ions, but NaHCO₃ (sodium bicarbonate) can produce hydrogen ions in a much smaller extent as it is an amphiprotic substance, meaning it can also act as an acid under certain circumstances.
3. NH₃ (ammonia) is a base and does not yield hydrogen ions, whereas HC₂H₃O₂ (acetic acid) does yield hydrogen ions.
4. NH₃ (ammonia) is a base, and NaHCO₃ (sodium bicarbonate) is typically considered a base as it tends to produce hydroxide ions (OH-) rather than hydrogen ions.

Thus, option 1 is the correct answer, as both H₂CO₃ and HC₂H₃O₂ are compounds that yield hydrogen ions as the only positive ions in an aqueous solution.