Question

Write balanced equations describing the reaction of \(\mathrm{Sr}\) with each of the following: \(\mathrm{O}_{2}, \mathrm{~S}, \mathrm{Cl}_{2}, \mathrm{P}_{4}, \mathrm{H}_{2}, \mathrm{H}_{2} \mathrm{O}\), and \(\mathrm{HCl}\).

Short answer

The balanced equations for the reactions of strontium (Sr) with the given substances are as follows: 1. \( 2\mathrm{Sr} + \mathrm{O}_{2} \rightarrow 2\mathrm{SrO} \) 2. \( \mathrm{Sr} + \mathrm{S} \rightarrow \mathrm{SrS} \) 3. \( \mathrm{Sr} + \mathrm{Cl}_{2} \rightarrow \mathrm{SrCl}_{2} \) 4. \( 6\mathrm{Sr} + \mathrm{P}_{4} \rightarrow 2\mathrm{Sr}_{3}\mathrm{P}_{2} \) 5. \( \mathrm{Sr} + \mathrm{H}_{2} \rightarrow \mathrm{SrH}_{2} \) 6. \( \mathrm{Sr} + 2\mathrm{H}_{2}\mathrm{O} \rightarrow \mathrm{Sr}(\mathrm{OH})_{2} + \mathrm{H}_{2} \) 7. \( \mathrm{Sr} + 2\mathrm{HCl} \rightarrow \mathrm{SrCl}_{2} + \mathrm{H}_{2} \)

Step-by-step solution

1. Reaction with Oxygen

: Strontium reacts with oxygen to form strontium oxide (SrO). In order to balance the equation, we can simply write: \[ \mathrm{2Sr} + \mathrm{O}_{2} \rightarrow 2\mathrm{SrO} \]

2. Reaction with Sulfur

: Strontium reacts with sulfur to form strontium sulfide (SrS). The balanced equation for this reaction can be written as: \[ \mathrm{Sr} + \mathrm{S} \rightarrow \mathrm{SrS} \]

3. Reaction with Chlorine

: Strontium reacts with chlorine to form strontium chloride (SrCl2). To balance the equation, we have: \[ \mathrm{Sr} + \mathrm{Cl}_{2} \rightarrow \mathrm{SrCl}_{2} \]

4. Reaction with Phosphorus

: Strontium reacts with phosphorus to form strontium phosphide (Sr3P2). The balanced equation for this reaction can be written as: \[ 6\mathrm{Sr} + \mathrm{P}_{4} \rightarrow 2\mathrm{Sr}_{3}\mathrm{P}_{2} \]

5. Reaction with Hydrogen

: Strontium reacts with hydrogen to form strontium hydride (SrH2). The balanced chemical equation for this reaction is: \[ \mathrm{Sr} + \mathrm{H}_{2} \rightarrow \mathrm{SrH}_{2} \]

6. Reaction with Water

: Strontium reacts with water to form strontium hydroxide (Sr(OH)2) and hydrogen gas (H2). The balanced equation for this reaction can be written as: \[ \mathrm{Sr} + 2\mathrm{H}_{2}\mathrm{O} \rightarrow \mathrm{Sr}(\mathrm{OH})_{2} + \mathrm{H}_{2} \]

7. Reaction with Hydrochloric Acid

: Finally, strontium reacts with hydrochloric acid (HCl) to form strontium chloride (SrCl2) and hydrogen gas (H2). This balanced equation is: \[ \mathrm{Sr} + 2\mathrm{HCl} \rightarrow \mathrm{SrCl}_{2} + \mathrm{H}_{2} \]

Key concepts

Balancing Chemical Equations

Balancing chemical equations is a fundamental skill in chemistry that ensures the law of conservation of mass is satisfied. In a chemical reaction, the mass of the reactants must be equal to the mass of the products. This means that the number of atoms for each element should be the same on both sides of the equation.
To balance equations, follow these steps:

• Write the unbalanced equation based on the reaction description.
• Count the number of atoms of each element in the reactants and products.
• Adjust coefficients to balance the atoms, beginning with elements that appear in only one reactant and one product.
• Repeat the process until all elements are balanced.
• Check your work to ensure mass conservation and see that you have used the simplest coefficients possible.

For example, in the reaction of strontium with oxygen to form strontium oxide, we begin with: \( \mathrm{Sr} + \mathrm{O}_{2} \rightarrow \mathrm{SrO} \). We balance it by adding a coefficient of 2 for both \( \mathrm{Sr} \) and \( \mathrm{SrO} \) to get: \( 2\mathrm{Sr} + \mathrm{O}_{2} \rightarrow 2\mathrm{SrO} \), thereby balancing the equation.

Strontium Reactions

Strontium is an alkaline earth metal known for its reactive nature, particularly with nonmetals. Understanding how strontium reacts with different substances allows us to see its role in forming various compounds. In its reactions:

• Strontium tends to lose two electrons to form \( \mathrm{Sr}^{2+} \).
• It readily reacts with the nonmetals like oxygen and sulfur to form the oxide \( \mathrm{SrO} \) and sulfide \( \mathrm{SrS} \).
• Reacts with chlorine to produce strontium chloride \( \mathrm{SrCl}_{2} \), a common strontium compound.
• With phosphorus, it forms strontium phosphide \( \mathrm{Sr}_{3}\mathrm{P}_{2} \) through a less common reaction.

These reactions highlight the typical behavior of strontium, involving the formation of ionic bonds with nonmetals.

Inorganic Chemistry

Inorganic chemistry deals with the properties and reactions of inorganic compounds, which include metals, minerals, and organometallics. This field is vast and includes the study of:

• Transition metals and their complex formation.
• Nonmetals and their unique bonding behaviors.
• Reactions, such as those involving strontium, to understand chemical reactivity patterns.

Inorganic chemistry is essential in the synthesis and application of materials, such as catalysts and advanced ceramics. For example, understanding how strontium reacts with water to form \( \mathrm{Sr}(\mathrm{OH})_{2} \) and hydrogen gas is part of grasping how bonds are formed and broken in inorganic reactions. Each reaction provides insights into the behavior of inorganic substances under different conditions.

Chemical Compounds

Chemical compounds are formed when two or more elements chemically bond together, resulting in a substance with unique properties. In reactions involving strontium, various compounds illustrate the nature and variety of chemical bonding:

• Strontium oxide \( \mathrm{SrO} \) and strontium sulfide \( \mathrm{SrS} \) are examples of ionic compounds formed by the direct bonding between strontium and nonmetals like oxygen and sulfur.
• Strontium chloride \( \mathrm{SrCl}_{2} \) demonstrates how halogens combine with metals to produce stable salts.
• The formation of strontium hydride \( \mathrm{SrH}_{2} \) shows metal-hydrogen bonding in hydrides.
• In complex compounds like strontium phosphide \( \mathrm{Sr}_{3}\mathrm{P}_{2} \), multiple atoms combine in specific ratios to form compounds with distinct crystal structures.

Understanding these compounds involves studying their chemical formulas, types of bondings, such as ionic or covalent, and their applications in both daily life and industrial processes.