Question

Write a balanced equation for each of the following reactions: (a) \(\mathrm{HCO}_{3}^{-}(a q)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow ?\) (b) \(\mathrm{CO}_{3}^{2-}(a q)+\mathrm{HNO}_{3}(a q) \longrightarrow ?\)

Short answer

(a) \( 2 \mathrm{HCO}_{3}^{-} + \mathrm{H}_2 \mathrm{SO}_4 \rightarrow 2 \mathrm{CO}_2 + 2 \mathrm{H}_2\mathrm{O} + \mathrm{SO}_4^{2-} \); (b) \( \mathrm{CO}_3^{2-} + 2 \mathrm{HNO}_3 \rightarrow \mathrm{CO}_2 + \mathrm{H}_2\mathrm{O} + 2 \mathrm{NO}_3^{-} \).

Step-by-step solution

Identify Reactants and Possible Products for Reaction (a)

For the reaction involving bicarbonate ion \( \mathrm{HCO}_{3}^{-} \) and sulfuric acid \( \mathrm{H}_{2} \mathrm{SO}_4 \), the products typically include carbon dioxide \( \mathrm{CO}_2 \), water \( \mathrm{H}_2\mathrm{O} \), and the sulfate ion \( \mathrm{SO}_4^{2-} \). Sulfuric acid donates \( \mathrm{H}^+ \) ions, which react with the bicarbonate ions, producing carbonic acid which decomposes into \( \mathrm{CO}_2 \) and \( \mathrm{H}_2\mathrm{O} \).

Write the Unbalanced Equation for Reaction (a)

The unbalanced chemical equation considering the identified products is: \[ \mathrm{HCO}_{3}^{-} (aq) + \mathrm{H}_2\mathrm{SO}_4 (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) + \mathrm{SO}_4^{2-} (aq) \]

Balance Equation for Reaction (a)

To balance the above equation, ensure the number of each type of atom on the reactant side equals the number on the product side. Balance the equation: \[ 2 \mathrm{HCO}_{3}^{-} (aq) + \mathrm{H}_2\mathrm{SO}_4 (aq) \rightarrow 2 \mathrm{CO}_2 (g) + 2 \mathrm{H}_2\mathrm{O} (l) + \mathrm{SO}_4^{2-} (aq) \]

Identify Reactants and Possible Products for Reaction (b)

For the carbonate ion \( \mathrm{CO}_3^{2-} \) reacting with nitric acid \( \mathrm{HNO}_3 \), the typical products are carbon dioxide \( \mathrm{CO}_2 \), water \( \mathrm{H}_2\mathrm{O} \), and the nitrate ion \( \mathrm{NO}_3^{-} \). The \( \mathrm{H}^+ \) from nitric acid reacts with the carbonate ions producing carbonic acid that decomposes into \( \mathrm{CO}_2 \) and \( \mathrm{H}_2\mathrm{O} \).

Write the Unbalanced Equation for Reaction (b)

The unbalanced chemical equation for these reactants is: \[ \mathrm{CO}_{3}^{2-} (aq) + \mathrm{HNO}_3 (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) + \mathrm{NO}_3^{-} (aq) \]

Balance Equation for Reaction (b)

Balance the equation to ensure atoms and charges are equal on both sides. The balanced equation is: \[ \mathrm{CO}_{3}^{2-} (aq) + 2 \mathrm{HNO}_3 (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) + 2 \mathrm{NO}_3^{-} (aq) \]

Key concepts

Balancing Chemical Equations

Balancing chemical equations is essential to ensure that the same number of each type of atom appears on both sides of the equation. This aligns with the law of conservation of mass, which states that matter cannot be created or destroyed in a closed system. For balancing, you need to:

• Count the number of atoms for each element in the reactants and products.
• Add coefficients in front of compounds to balance the atoms for each element on both sides.
• Adjust coefficients as necessary to achieve balance.

It's important to note that you should never change the subscripts in a chemical formula to balance it since that alters the compound's identity.

Bicarbonate and Sulfuric Acid Reaction

When bicarbonate ions \(\mathrm{HCO}_3^-\) react with sulfuric acid \(\mathrm{H}_2\mathrm{SO}_4\), a typical set of products are formed: carbon dioxide \(\mathrm{CO}_2\), water \(\mathrm{H}_2\mathrm{O}\), and sulfate ions \(\mathrm{SO}_4^{2-}\). In this reaction:

• The hydrochloric acid donates \(\mathrm{H}^+\) ions.
• The bicarbonate ion, \(\mathrm{HCO}_3^-\), accepts these ions to form carbonic acid \(\mathrm{H}_2\mathrm{CO}_3\).
• Carbonic acid is unstable and decomposes to form carbon dioxide and water.

To balance the initial unbalanced equation:\[ \mathrm{HCO}_{3}^{-} (aq) + \mathrm{H}_2\mathrm{SO}_4 (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) + \mathrm{SO}_4^{2-} (aq) \]Appropriately adjust coefficients:\[ 2 \mathrm{HCO}_{3}^{-} (aq) + \mathrm{H}_2\mathrm{SO}_4 (aq) \rightarrow 2 \mathrm{CO}_2 (g) + 2 \mathrm{H}_2\mathrm{O} (l) + \mathrm{SO}_4^{2-} (aq) \]Ensuring all atoms and ions are balanced.

Carbonate and Nitric Acid Reaction

In the reaction between carbonate ions \(\mathrm{CO}_3^{2-}\) and nitric acid \(\mathrm{HNO}_3\), carbon dioxide, water, and nitrate ions \(\mathrm{NO}_3^-\) are formed. This process involves:

• The donation of \(\mathrm{H}^+\) ions by nitric acid.
• These ions react with \(\mathrm{CO}_3^{2-}\) to form carbonic acid, which rapidly decomposes into carbon dioxide \(\mathrm{CO}_2\) and water \(\mathrm{H}_2\mathrm{O}\).

The initial unbalanced equation is:\[ \mathrm{CO}_{3}^{2-} (aq) + \mathrm{HNO}_3 (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) + \mathrm{NO}_3^{-} (aq) \]To balance, adjust the coefficients:\[ \mathrm{CO}_{3}^{2-} (aq) + 2 \mathrm{HNO}_3 (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) + 2 \mathrm{NO}_3^{-} (aq) \]This balanced form ensures that the number of atoms and charges is equal on both sides.

Acid-Base Reactions

Acid-base reactions are fundamental chemical processes where an acid donates a proton (\(\mathrm{H}^+\)) and a base accepts it. These reactions are generally characterized by the exchange of \(\mathrm{H}^+\) ions between reactants, leading to neutralization. Common properties include:

• Producing water from hydroxide (\(\mathrm{OH}^-\)) and \(\mathrm{H}^+\) ions.
• Formation of a salt, comprising the remaining parts of the acid and base.

For example, in the bicarbonate and sulfuric acid reaction, the \(\mathrm{H}^+\) ions from the acid interact with the base, \(\mathrm{HCO}_3^{-}\). This leads to the formation of carbonic acid and eventually to carbon dioxide and water.Acid-base reactions are crucial across various fields, including biological systems, industrial processes, and environmental contexts.