Question

A tablet of one antacid contains citric acid, H3C6H5O7, and sodium hydrogen carbonate, NaHCO3. When the tablet dissolves in water, bubbles of CO2 are produced. This reaction is represented by the incomplete equation below.
H3C6H5O7(aq) + 3NaHCO3(aq)==> Na3C6H5O7(aq) + 3CO2(g) + 3 _______ (ℓ)
Complete the equation in your answer booklet by writing the formula of the missing product.

Answer 1

H2O
This equation is a double displacement reaction, and it forms H2CO3, which is very unstable and separates into H2O and CO2.

Answer 2

Answer:

Water (H₂O) is the missing product

Explanation:

Let's write the equation involved:

H₃C₆H₅O₇(aq) + 3NaHCO₃(aq) ---->

When we watch the first product which is Na₃C₆H₅O₇, we can see that in this case, there was a displacement of the H₃ by the atoms of Na. This give us an idea of what kind of reaction is ocurring. If we follow the principle of the displacement, the reaction should be the following:

H₃C₆H₅O₇(aq) + 3NaHCO₃(aq) ----> Na₃C₆H₅O₇(aq) + 3H₂CO₃(aq)

However, this last compound (H₂CO₃) is very unstable in the presence of sodium citrate, so, the acid suffers another internal reaction:

H₂CO₃(aq) -------> CO₂(g) + H₂O(l)

The CO₂ are the bubbles produced, and the water is produced in solution. Therefore, the products of the general reaction is:

H₃C₆H₅O₇(aq) + 3NaHCO₃(aq) ----> Na₃C₆H₅O₇(aq) + 3CO₂(g) + 3H₂O(l)