Question

Write balanced equations describing the reaction of lithium metal with each of the following: \(\mathrm{O}_{2}, \mathrm{S}, \mathrm{Cl}_{2}, \mathrm{P}_{2}, \mathrm{H}_{2}, \mathrm{H}_{2} \mathrm{O},\) and \(\mathrm{HCl} .\)

Short answer

The balanced equations for the reactions of lithium with the given elements and compounds are as follows: 1. \(4 \mathrm{Li}(s) + \mathrm{O}_{2}(g) \rightarrow 2 \mathrm{Li}_{2} \mathrm{O}(s)\) 2. \(2 \mathrm{Li}(s) + \mathrm{S}(s) \rightarrow \mathrm{Li}_{2} \mathrm{S}(s)\) 3. \(2 \mathrm{Li}(s) + \mathrm{Cl}_{2}(g) \rightarrow 2 \mathrm{LiCl}(s)\) 4. \(6 \mathrm{Li}(s) + \mathrm{P}_{2}(s) \rightarrow 2 \mathrm{Li}_{3} \mathrm{P}(s)\) 5. \(2 \mathrm{Li}(s) + \mathrm{H}_{2}(g) \rightarrow 2 \mathrm{LiH}(s)\) 6. \(2 \mathrm{Li}(s) + 2 \mathrm{H}_{2} \mathrm{O}(l) \rightarrow 2 \mathrm{LiOH}(aq) + \mathrm{H}_{2}(g)\) 7. \(2 \mathrm{Li}(s) + 2 \mathrm{HCl}(aq) \rightarrow 2 \mathrm{LiCl}(aq) + \mathrm{H}_{2}(g)\)

Step-by-step solution

Reaction with O₂

When lithium reacts with oxygen, it forms lithium oxide, Li₂O. The balanced chemical equation is: $$ 4 \mathrm{Li}(s) + \mathrm{O}_{2}(g) \rightarrow 2 \mathrm{Li}_{2} \mathrm{O}(s) $$

Reaction with S

When lithium reacts with sulfur, it forms lithium sulfide, Li₂S. The balanced chemical equation is: $$ 2 \mathrm{Li}(s) + \mathrm{S}(s) \rightarrow \mathrm{Li}_{2} \mathrm{S}(s) $$

Reaction with Cl₂

When lithium reacts with chlorine, it forms lithium chloride, LiCl. The balanced chemical equation is: $$ 2 \mathrm{Li}(s) + \mathrm{Cl}_{2}(g) \rightarrow 2 \mathrm{LiCl}(s) $$

Reaction with P₂

When lithium reacts with phosphorus, it forms lithium phosphide, Li₃P. The balanced chemical equation is: $$ 6 \mathrm{Li}(s) + \mathrm{P}_{2}(s) \rightarrow 2 \mathrm{Li}_{3} \mathrm{P}(s) $$

Reaction with H₂

When lithium reacts with hydrogen, it forms lithium hydride, LiH. The balanced chemical equation is: $$ 2 \mathrm{Li}(s) + \mathrm{H}_{2}(g) \rightarrow 2 \mathrm{LiH}(s) $$

Reaction with H₂O

When lithium reacts with water, it forms lithium hydroxide, LiOH, and hydrogen gas. The balanced chemical equation is: $$ 2 \mathrm{Li}(s) + 2 \mathrm{H}_{2} \mathrm{O}(l) \rightarrow 2 \mathrm{LiOH}(aq) + \mathrm{H}_{2}(g) $$

Reaction with HCl

When lithium reacts with hydrochloric acid, it forms lithium chloride, LiCl, and hydrogen gas. The balanced chemical equation is: $$ 2 \mathrm{Li}(s) + 2 \mathrm{HCl}(aq) \rightarrow 2 \mathrm{LiCl}(aq) + \mathrm{H}_{2}(g) $$

Key concepts

Balancing Equations

Balancing chemical equations is an important skill in chemistry. It involves making sure that there are equal numbers of each type of atom on both sides of the chemical equation. This ensures that we obey the law of conservation of mass, which states that mass cannot be created or destroyed in a chemical reaction. To balance an equation, you'll have to account for each element involved by adjusting coefficients.

• Check each element one by one to make sure that you have the same number on both sides of the equation.
• If an element appears more than once on either side, keep tweaking the coefficients until all elements are balanced.
• Re-check the entire equation to confirm that the reaction is fully balanced.

Balancing equations takes practice, but once you understand the core principles, it becomes a straightforward task.

Reaction of Lithium

Lithium is a highly reactive metal that participates in various chemical reactions. It reacts readily with gases and non-metals such as oxygen (\(\mathrm{O}_2\)), sulfur (\(\mathrm{S}\)), and chlorine (\(\mathrm{Cl}_2\)). These reactions often release a significant amount of energy.
For example, when lithium reacts with oxygen, it forms lithium oxide:\[4 \mathrm{Li}(s) + \mathrm{O}_{2}(g) \rightarrow 2 \mathrm{Li}_{2} \mathrm{O}(s)\]Lithium also reacts with water and acids like hydrochloric acid to form hydrogen gas. This showcases its ability to participate in both synthesis and single replacement reactions. These properties make lithium an interesting element to study in basic chemistry.

Chemistry Education

A solid understanding of chemistry is crucial to understanding the world around us. Chemistry education provides us with the tools to understand complex interactions at the molecular level. It involves various concepts, not just balancing equations but understanding the properties and reactions of different elements, like lithium.
Studying chemical reactions helps us comprehend processes occurring in nature and everyday life. It also aids in developing problem-solving skills as students learn to write and balance equations and predict the outcomes of reactions. Teaching and learning chemistry encourages critical thinking and connects theoretical knowledge with real-world applications.

• Promotes scientific literacy necessary for everyday decision making.
• Complements other scientific disciplines such as physics and biology.
• Enhances understanding of technological advancements.

Teaching Chemical Equations

Teaching chemical equations involves more than just writing out reactions. It’s about helping students understand why reactions happen and how to represent them accurately with balanced equations. Effective teaching strategies include:

• Using models and visual aids to show how atoms and molecules interact.
• Incorporating hands-on experiments that illustrate chemical reactions.
• Breaking down complex reactions into smaller, more understandable steps.
• Utilizing software and online tools to simulate chemical reactions.

Engaging students in active learning by encouraging them to predict reaction outcomes and explore different scenarios fosters a positive learning environment. Teachers also play a pivotal role by showing real-life applications of chemistry concepts to maintain student interest and motivation.