Question

Two "driving forces" for reactions discussed in this section are the formation of water in an acid-base reaction and the formation of a gaseous product. Write balanced chemical equations showing two examples of each type.

Short answer

Here are the balanced chemical equations for the given reactions: 1. Acid-Base Reaction 1: \(HCl(aq) + NaOH(aq) \rightarrow H_2O(l) + NaCl(aq)\) 2. Acid-Base Reaction 2: \(H_2SO_4(aq) + 2 KOH(aq) \rightarrow 2 H_2O(l) + K_2SO_4(aq)\) 3. Gaseous Product Reaction 1: \(NaHCO_3(s) + CH_3COOH(l) \rightarrow H_2O(l) + CO_2(g) + CH_3COONa(aq)\) 4. Gaseous Product Reaction 2: \(CaCO_3(s) + 2 HCl(aq) \rightarrow H_2O(l) + CO_2(g) + CaCl_2(aq)\)

Step-by-step solution

Acid-Base Reaction 1: Hydrochloric acid and Sodium hydroxide

In this reaction, hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH) to form water (H2O) and sodium chloride (NaCl). The balanced chemical equation for this reaction can be written as follows: \(HCl(aq) + NaOH(aq) \rightarrow H_2O(l) + NaCl(aq)\)

Acid-Base Reaction 2: Sulfuric acid and Potassium hydroxide

In this reaction, sulfuric acid (H2SO4) reacts with potassium hydroxide (KOH) to form water (H2O) and potassium sulfate (K2SO4). The balanced chemical equation for this reaction can be written as follows: \(H_2SO_4(aq) + 2 KOH(aq) \rightarrow 2 H_2O(l) + K_2SO_4(aq)\)

Gaseous Product Reaction 1: Sodium bicarbonate and Acetic acid

In this reaction, sodium bicarbonate (NaHCO3) reacts with acetic acid (CH3COOH) to form a gaseous product, carbon dioxide (CO2), as well as water (H2O) and sodium acetate (CH3COONa). The balanced chemical equation for this reaction can be written as follows: \(NaHCO_3(s) + CH_3COOH(l) \rightarrow H_2O(l) + CO_2(g) + CH_3COONa(aq)\)

Gaseous Product Reaction 2: Calcium carbonate and Hydrochloric acid

In this reaction, calcium carbonate (CaCO3) reacts with hydrochloric acid (HCl) to form a gaseous product, carbon dioxide (CO2), as well as water (H2O) and calcium chloride (CaCl2). The balanced chemical equation for this reaction can be written as follows: \(CaCO_3(s) + 2 HCl(aq) \rightarrow H_2O(l) + CO_2(g) + CaCl_2(aq)\)

Key concepts

Acid-Base Reactions

Acid-base reactions are fundamental chemical processes where an acid reacts with a base to form water and a salt. This type of reaction is crucial because it involves the transfer of protons (H+) between the reactants.
In our examples, we saw hydrochloric acid (HCl) reacting with sodium hydroxide (NaOH) to produce water ( H2O ) and sodium chloride ( NaCl ). Another classic acid-base reaction involves sulfuric acid ( H2SO4 ) reacting with potassium hydroxide ( KOH ), which forms water and potassium sulfate ( K2SO4 ). These reactions are important in various applications, from industrial processes to biological systems.
Acid-base reactions are often used in titrations, where one reactant is added gradually to the other until the reaction is complete, helping to determine concentrations.

Balanced Chemical Equations

Balanced chemical equations are essential for showing the exact proportions of reactants and products in a chemical reaction. Balancing an equation means making sure that the number of atoms for each element is the same on both sides of the reaction.
For instance, in the equation for the reaction between hydrochloric acid and sodium hydroxide: \(HCl(aq) + NaOH(aq) \rightarrow H2O(l) + NaCl(aq)\), both sides have one hydrogen, one chlorine, one sodium, and one oxygen atom.
Balancing helps to understand the stoichiometry of a reaction, which is crucial for calculating reactant or product masses needed in industrial chemical processes.

Gaseous Product Formation

Some chemical reactions result in the formation of a gas as a product, which can act as a driving force by shifting equilibrium and completing the reaction. Gaseous products are often visually noticeable due to bubbling or effervescence during reactions.
A common example is the reaction between sodium bicarbonate ( NaHCO3 ) and acetic acid ( CH3COOH ), which produces carbon dioxide ( CO2 ), visible as bubbles. Another example is when calcium carbonate ( CaCO3 ) reacts with hydrochloric acid ( HCl ), which also produces carbon dioxide.
These reactions are not only important for theoretical chemistry but also have practical implications, such as in baking, where carbon dioxide helps dough rise.

Acid Reactions

Acid reactions involve the release of hydrogen ions (H+) into a solution. These reactions can occur with metals, bases, and carbonates, among others. Acids are typically sour and corrosive, and they play significant roles in various scientific and industrial processes.
In our examples, we saw how acids like sulfuric and hydrochloric acids reacted with bases to form water, and with carbonates like calcium carbonate to release gases.
Acid reactions are crucial in everyday life, from the digestion of food in our stomachs (where hydrochloric acid plays a key role) to the cleaning of metals and manufacturing of fertilizers.

Driving Forces in Chemistry

Driving forces in chemistry are the factors that make a reaction occur. Two main driving forces are the formation of water in acid-base reactions and the formation of gaseous products.

• The formation of water reduces the number of free ions in solution, driving the reaction to completion.
• Gaseous products, when formed, escape from the reaction mixture, prodding the reaction to proceed forward.

This principle is exploited in many chemical processes, from the synthesis of materials to environmental applications like gas scrubbing. Understanding these driving forces helps chemists design reactions that are efficient and effective.