Question

Write a balanced chemical equation for the reaction between lithium metal and chlorine gas.

Short answer

The balanced chemical equation for the reaction between lithium metal and chlorine gas is: \(2 Li + Cl_2 \rightarrow 2 LiCl\).

Step-by-step solution

Identify the Reactants

Determine the chemical symbols for lithium and chlorine. Lithium is represented by 'Li' and chlorine gas is diatomic and represented by 'Cl_2'.

Write the Unbalanced Equation

Write the reactants on the left side and the products on the right side of the equation. Since lithium is a metal and chlorine is a nonmetal, they will react to form an ionic compound, lithium chloride (LiCl). The unbalanced equation is 'Li + Cl_2 -> LiCl'.

Determine the Products

Predict the formula of the product formed when lithium reacts with chlorine. Lithium has a +1 charge and chlorine has a -1 charge, so they combine in a 1:1 ratio to form lithium chloride, LiCl.

Balance the Equation

Balance the equation by ensuring that there are equal numbers of each type of atom on both sides of the equation. The balanced equation is '2 Li + Cl_2 -> 2 LiCl'.

Review and Confirm the Balanced Equation

Verify that the coefficients of the balanced equation are in the simplest whole number ratio and that the law of conservation of mass is satisfied.

Key concepts

Chemical Reactions

Understanding chemical reactions begins with recognizing that substances, known as reactants, undergo chemical changes to form new substances, known as products. In a reaction, the molecules of the reactants interact to break bonds and form new bonds, resulting in different compounds with unique properties.

For example, when lithium metal reacts with chlorine gas, a chemical reaction occurs in which the elements form an ionic compound. This reaction can be depicted through a chemical equation that showcases the transformation from reactants to products. Balancing this equation is critical to reflect the reactants' conversion to products accurately.

Ionic Compounds

Ionic compounds are formed when metals react with nonmetals, causing electrons to be transferred from the metal atoms to the nonmetal atoms. This transfer creates ions: positively charged metal ions (cations) and negatively charged nonmetal ions (anions). These ions are held together by strong electrostatic forces, known as ionic bonds.

In the reaction between lithium and chlorine, lithium loses an electron to become a lithium ion with a +1 charge, while chlorine gains an electron to form a chloride ion with a -1 charge. The resultant lithium chloride consists of a repeating pattern of lithium and chloride ions, held together in a crystal lattice structure.

Law of Conservation of Mass

The law of conservation of mass is a fundamental principle stating that in a closed system, mass is neither created nor destroyed during a chemical reaction. This means that the mass of the reactants must equal the mass of the products. It implies that all atoms present in the reactants must be accounted for among the products.

When balancing the equation for the reaction between lithium and chlorine, we ensure that the number of lithium and chlorine atoms on each side of the equation is the same, thus fulfilling the requirements of the law of conservation of mass. This principle underlines the necessity of a balanced chemical equation.

Stoichiometry

Stoichiometry is a section of chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction. It involves the use of coefficients in a balanced chemical equation to predict the amounts of reactants required and products formed.

For the lithium and chlorine reaction, stoichiometry helps us understand that two moles of lithium metal react with one mole of chlorine gas to produce two moles of lithium chloride. By mastering stoichiometry, students can predict the outcomes of chemical reactions, customize reaction conditions, and even calculate the yield of a reaction.