Question

Write a balanced equation for the reaction between calcium oxide and dilute \(\mathrm{HCl}\) solution.

Short answer

The balanced chemical equation is: \( \text{CaO} + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} \).

Step-by-step solution

Understanding the Reactants

Calcium oxide, \(\text{CaO}\), is a basic oxide, while hydrochloric acid, \(\text{HCl}\), is an acid. When they react, they produce a salt and water. This is an example of a neutralization reaction.

Identifying the Products

The products of the reaction between \(\text{CaO}\) and \(\text{HCl}\) are calcium chloride ( ext{CaCl}_2) and water ( ext{H}_2 ext{O}). Therefore, the reaction is: \[ \text{CaO} + \text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} \]

Balancing the Equation

Count the number of each type of atom on both sides of the equation and adjust the coefficients to balance them. In the unbalanced equation: \[ \text{CaO} + \text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} \] we have:- Calcium (Ca): 1 on both sides- Oxygen (O): 1 on both sides- Hydrogen (H): 1 on the left, 2 on the right- Chlorine (Cl): 1 on the left, 2 on the rightTo balance hydrogen and chlorine, update the equation:\[ \text{CaO} + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} \]Now, we have:- Calcium (Ca): 1 on both sides- Oxygen (O): 1 on both sides- Hydrogen (H): 2 on both sides- Chlorine (Cl): 2 on both sides, which is balanced.

Key concepts

Balancing Chemical Equations

Balancing chemical equations involves making sure that the number of atoms for each element is equal on both sides of the chemical equation. It's a crucial part of chemistry that ensures the law of conservation of mass is satisfied.
When a chemical equation is unbalanced, it means that the number of atoms for some elements on the reactant side does not match the number on the product side. This can be quite common initially.
To balance a chemical equation, follow these simple steps:

• Write down the unbalanced equation.
• List the number of atoms of each element present in both reactants and products.
• Adjust the coefficients (the numbers in front of molecules) to balance the atoms for each element.
• Check your work to ensure all elements are balanced.

Balancing helps in understanding the correct proportions of reactants and products, and it’s essential for calculations in reaction stoichiometry.

Neutralization Reaction

Neutralization reactions are a type of chemical reaction where an acid and a base react to form water and a salt. They are important in various real-world applications, such as digestion, medicine, and environmental chemistry.
The general equation for a neutralization reaction is:\[ \text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water} \]For instance, in the reaction of calcium oxide (\( \text{CaO} \)) and hydrochloric acid (\( \text{HCl} \)), the base \( \text{CaO} \) neutralizes the acid \( \text{HCl} \) to produce calcium chloride (\( \text{CaCl}_2 \)) and water (\( \text{H}_2\text{O} \)). This is an example of a simple neutralization reaction.
Neutralization reactions are exothermic, meaning they release heat. Additionally, they can be used to adjust the pH of solutions, which is essential in fields like agriculture, medicine, and wastewater treatment.

Reactants and Products

In any chemical reaction, we start with substances called reactants, which undergo chemical changes to form new substances known as products. Grasping the difference between reactants and products is essential for understanding chemical equations and reactions.
Reactants are the starting materials in a reaction. They are present before the chemical change occurs; for example, in our exercise, calcium oxide (\( \text{CaO} \)) and hydrochloric acid (\( \text{HCl} \)) are the reactants.
Products, on the other hand, are the substances that are formed as a result of the chemical reaction. They appear on the right side of the chemical equation. In the exercise, calcium chloride (\( \text{CaCl}_2 \)) and water (\( \text{H}_2\text{O} \)) are products of the reaction.
The key difference between reactants and products lies in their chemical properties. New properties are seen in products because they are entirely different substances formed through the rearrangement of atoms from the reactants.