Acid-Base Reactions: Videos & Practice Problems

Acid-base reactions involve various interactions, such as acids with hydroxide bases, neutral amines, metals, and metal oxides. These reactions typically produce water and a salt, an ionic compound. For instance, nitric acid and ammonia yield ammonium nitrate, while sulfuric acid and metals generate hydrogen gas and a corresponding salt. Understanding these patterns helps predict products formed in acid-base reactions, emphasizing the role of weak bases like neutral amines and the significance of ionic compounds in these processes.

Acid-Base Reactions Concept 1

Acid-base reactions are fundamental chemical processes that involve the interaction of acids with various substances, leading to the formation of different products. One common type of reaction occurs when acids react with hydroxide bases, represented by the hydroxide ion (OH^-). In this scenario, the acid donates a proton (H⁺), which combines with the hydroxide ion to produce water (H₂O) and a salt, an ionic compound. For example, when hydrobromic acid (HBr) reacts with lithium hydroxide (LiOH), the products are water and lithium bromide (LiBr), an aqueous salt.

Another type of acid-base reaction involves neutral amines, which are weak bases containing nitrogen and hydrogen, or carbon, nitrogen, and hydrogen. A classic example is the reaction between nitric acid (HNO₃) and ammonia (NH₃). This reaction produces ammonium nitrate (NH₄NO₃), a salt formed from the combination of the acid and the amine.

Acids can also react with metals, such as sodium, potassium, magnesium, and zinc. In these reactions, the acid reacts with the metal to produce hydrogen gas (H₂) and a salt. For instance, when sulfuric acid (H₂SO₄) reacts with iron (Fe), hydrogen gas is released, and iron(II) sulfate (FeSO₄) is formed as a salt.

Lastly, acids can react with metal oxides, which include compounds like lithium oxide (Li₂O) and iron(II) oxide (FeO). The reaction between an acid and a metal oxide results in the formation of water and a salt. For example, when hydrochloric acid (HCl) reacts with iron(II) oxide, it produces water and iron(II) chloride (FeCl₂).

Understanding these patterns of acid-base reactions is crucial for predicting the products formed based on the type of acid and the reacting substance. Recognizing the nature of the reactants allows for effective identification of the resulting compounds in these chemical processes.

Acid-Base Reactions Example 1

In the reaction between hydrofluoric acid (HF) and potassium hydroxide (KOH), a double displacement reaction occurs. In this process, the hydrogen ion (H⁺) from hydrofluoric acid combines with the hydroxide ion (OH⁻) from potassium hydroxide to form water (H₂O). Simultaneously, the potassium ion (K⁺) from potassium hydroxide pairs with the fluoride ion (F⁻) from hydrofluoric acid to produce potassium fluoride (KF) in an aqueous solution.The balanced chemical equation for this reaction can be represented as follows:\[\text{HF (aq)} + \text{KOH (aq)} \rightarrow \text{H}_2\text{O (l)} + \text{KF (aq)}\]In this equation, each compound has a coefficient of 1, indicating that one mole of each reactant yields one mole of each product. This reaction exemplifies the principles of acid-base neutralization, where an acid reacts with a base to produce water and a salt, highlighting the concept of opposites attracting in ionic interactions.

Write a balanced chemical equation for the following acid-base reaction:
Bromic acid reacting with hydrazine (N₂H₄).

• A. HBrO₃ (aq) + N₂H₄ (aq) → N₂H₅BrO₃ (aq)
• B. HBrO4 (aq) + N2H4 (aq) → N₂H₅BrO₄ (aq)
• C. HBrO3 (aq) + N2H4 (aq) → H₂BrO₃ (aq) + N₂H₃^– (aq)
• D. HBrO₄ (aq) + N₂H₄ (aq) → BrO₄^– (aq) + N₂H₄⁺ (aq)

Answer: (A)

Write a balanced chemical equation, include phases, for the following acid reaction:HClO₃ reacting with Zn metal.

• A. HClO₃(aq) + Zn(l) → ZnClO₃(aq) + H(g)
• B. 2 HClO₃(aq) + Zn(l) → Zn(ClO₃)₂(aq) + 2 H(g)
• C. 2 HClO₃(aq) + 2 Zn(s) → 2 ZnClO₃(aq) + H₂(g)
• D. 2 HClO₃(aq) + Zn(s) → Zn(ClO₃)2(aq) + H₂(g)

Answer: (D)

Write a balanced chemical equation, include phases, for the following acid reaction:HBr reacting with Li₂O.

• A. 2 HBr(aq) + Li₂O(s) → H₂O(l) + 2 LiBr(aq)
• B. 2 HBr(aq) + Li₂O(s) → H₂(g) + 2 LiBrO(aq)
• C. 2 HBr(aq) + Li₂O(s) → 2 HO(aq) + 2 LiBr(aq)
• D. HBr(aq) + Li₂O(aq) → H₂O(l) + 2 LiBr(s)

Answer: (A)

Here’s what students ask on this topic:

What are the products of an acid reacting with a hydroxide base?

When an acid reacts with a hydroxide base, the products are water and a salt. The general reaction can be represented as:

$H_{+}+{\mathrm{OH}}_{-}\to H_{2}O$

For example, when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), the products are water (H₂O) and sodium chloride (NaCl):

${\mathrm{HCl}}_{+}$

How do acids react with neutral amines?

Acids react with neutral amines, which are weak bases, to form a salt. A common example is the reaction between nitric acid (HNO₃) and ammonia (NH₃), producing ammonium nitrate (NH₄NO₃):

${\mathrm{HNO}}_3+{\mathrm{NH}}_3\to {\mathrm{NH}}_4{\mathrm{NO}}_3$

This reaction involves the transfer of a proton (H⁺) from the acid to the amine, resulting in the formation of an ionic compound, which is the salt.

What happens when acids react with metals?

When acids react with metals, they typically produce hydrogen gas (H₂) and a salt. For example, when sulfuric acid (H₂SO₄) reacts with iron (Fe), the products are hydrogen gas and iron(II) sulfate (FeSO₄):

$H_2{\mathrm{SO}}_4+{\mathrm{Fe}}_{}\to H_2+{\mathrm{FeSO}}_4$

The reaction involves the acid donating protons (H⁺) to the metal, which releases hydrogen gas and forms a salt.

What are the products of an acid reacting with a metal oxide?

When an acid reacts with a metal oxide, the products are water and a salt. For example, when hydrochloric acid (HCl) reacts with iron(II) oxide (FeO), the products are water (H₂O) and iron(II) chloride (FeCl₂):

${\mathrm{HCl}}_{+}$

The reaction involves the acid donating protons (H⁺) to the metal oxide, resulting in the formation of water and a salt.

Why are neutral amines considered weak bases in acid-base reactions?

Neutral amines are considered weak bases in acid-base reactions because they have a lone pair of electrons on the nitrogen atom, which can accept a proton (H⁺) from an acid. However, they do not completely dissociate in water, which is a characteristic of weak bases. For example, ammonia (NH₃) can accept a proton to form ammonium (NH₄⁺), but this reaction is not complete:

${\mathrm{NH}}_3+H_{+}\to {\mathrm{NH}}_4+$

This partial dissociation is why neutral amines are classified as weak bases.