Question

Carbon dioxide gas and calcium oxide are produced when calcium carbonate, \(\mathrm{CaCO}_{3}\), is heated strongly. Write the balanced equation for this process.

Short answer

The balanced equation for the decomposition of calcium carbonate when heated is: \( \mathrm{CaCO}_{3} \xrightarrow{\Delta} \mathrm{CaO} + \mathrm{CO}_{2} \).

Step-by-step solution

Write down the unbalanced equation

First, we write down the unbalanced reaction equation involving reactants and products as given in the problem: \( \mathrm{CaCO}_{3} \xrightarrow{\Delta} \mathrm{CaO} + \mathrm{CO}_{2} \)

Count the atoms for each element

On the left (reactant) side of the equation, we have: - 1 calcium atom - 1 carbon atom - 3 oxygen atoms On the right (product) side of the equation, we have: - 1 calcium atom - 1 carbon atom - 3 oxygen atoms (2 from CO2 and 1 from CaO)

Check if the equation is balanced

Since the number of atoms for each element is the same on both sides, the equation is already balanced: \( \mathrm{CaCO}_{3} \xrightarrow{\Delta} \mathrm{CaO} + \mathrm{CO}_{2} \) The balanced equation for the decomposition of calcium carbonate when heated is: \( \mathrm{CaCO}_{3} \xrightarrow{\Delta} \mathrm{CaO} + \mathrm{CO}_{2} \)

Key concepts

Decomposition Reactions

Decomposition reactions are a type of chemical reaction where a single compound breaks down into simpler compounds or elemental substances. When heat, indicated by the symbol \( \Delta \), is applied to certain compounds, they undergo this decomposition process. An example is the heating of calcium carbonate, \( \mathrm{CaCO}_{3} \) to produce calcium oxide, \( \mathrm{CaO} \) and carbon dioxide gas, \( \mathrm{CO}_{2} \).

In the given exercise, calcium carbonate's thermal decomposition is utilized to illustrate such a reaction. Understanding these reactions is crucial for various applications, including the manufacturing of cement and the preparation of gases used in laboratories. The overarching principle is to recognize that in such reactions, complex molecules are transformed into simpler ones, usually with the aid of external energy sources like heat.

• Decomposition reactions often require an energy input.
• They result in the production of simpler substances from a single compound.
• Decomposition is the opposite process of synthesis reactions, where simpler substances combine to form a complex compound.

Chemical Stoichiometry

Chemical stoichiometry is the quantitative relationship between reactants and products in a chemical reaction. It is crucial for predicting yields and scaling up reactions for industrial applications. Stoichiometry is based on the law of conservation of mass, which states that in a closed system, matter is neither created nor destroyed. This principle requires that the number of atoms for each element in the reactants must be equal to the number in the products.

Our example involving calcium carbonate's decomposition involves ratios of 1:1:1 for \( \mathrm{CaCO}_{3} \) to \( \mathrm{CaO} \) and \( \mathrm{CO}_{2} \). The stoichiometric coefficients, in this case, all happen to be 1, reflecting an equal amount of moles of each substance involved in the reaction. Understanding stoichiometry can be pivotal for conducting experiments successfully and efficiently. It aids in the preparation of reactants and the prediction of the amount of product that will form.

• Stoichiometry is contingent upon the conservation of mass and atoms.
• It involves using balanced equations to calculate the masses or volumes of reactants and products.
• Stoichiometric coefficients indicate the proportion of molecules or moles in the reaction.

Chemical Equation Balancing

Balancing chemical equations is an essential skill in chemistry that allows us to apply the law of conservation of mass to chemical reactions. To balance an equation, the same number of atoms of each element must appear on both sides of the equation. When balancing equations, we adjust the coefficients—the numbers placed before compounds—to achieve this balance without altering the chemical identity of the substances involved.

Consider the decomposition of calcium carbonate. Initially, we have an unbalanced equation and then proceed to count and compare the number of each type of atom in the reactants and products. Fortuitously, in our example, the initial equation is already balanced. This is not always the case, and some equations may require iterative adjustment of coefficients. When done correctly, a balanced equation ensures that the mass of the reactants equals the mass of the products, staying true to the conservation principle.

• Correctly balancing equations is necessary for accurate stoichiometric calculations.
• Changing coefficients, not subscripts in formulas, is the proper way to balance equations.
• While some straightforward reactions may be intuitively balanced, more complex reactions often require a systematic approach to ensure accuracy.