Problem 122 - General Chemistry

Question

What is the phosphorus compound used in "strike anywhere" matches. What is the chemical equation for the burning of this compound in air?

Step-by-Step Solution

Answer

The phosphorus compound is phosphorus sesquisulfide \( P_4S_3 \). The chemical equation is \( P_4S_3 + 8O_2 \rightarrow P_4O_{10} + 3SO_2 \).

Step 1: Identify the Phosphorus Compound

The phosphorus compound used in 'strike anywhere' matches is phosphorus sesquisulfide. Its chemical formula is \( P_4S_3 \).

Step 2: Define the Burning Process

When phosphorus sesquisulfide \( P_4S_3 \) burns in air, it reacts with oxygen \( O_2 \) to produce phosphorus pentoxide \( P_4O_{10} \) and sulfur dioxide \( SO_2 \).

Step 3: Write the Balanced Chemical Equation

The balanced chemical equation for the burning of phosphorus sesquisulfide \( P_4S_3 \) in air is: \[ P_4S_3 + 8O_2 \rightarrow P_4O_{10} + 3SO_2 \]. This equation shows the reactants and products along with their stoichiometric coefficients.

Key Concepts

Chemical Equation

A chemical equation is a symbolic representation of a chemical reaction. It shows the reactants turning into products. In chemistry, chemical equations help us understand the transformation of substances during a reaction.

• The symbols in a chemical equation represent elements and compounds.
• Coefficients indicate the number of molecules or atoms of each substance involved in the reaction.

For example, in the chemical reaction for the burning of phosphorus sesquisulfide, the equation involves chemical symbols and coefficients, making it clear which substances are reacting and what products they form. Understanding this is crucial for analyzing chemical processes.

Burning Process

The burning process, also known as combustion, involves a chemical reaction where a substance reacts rapidly with oxygen, releasing energy in the form of light and heat. When phosphorus sesquisulfide burns, it undergoes a high-energy transformation.

• The compound reacts with oxygen molecules from the air.
• This interaction breaks and forms chemical bonds, resulting in new substances.

In the particular case of phosphorus sesquisulfide, burning leads to the production of phosphorus pentoxide and sulfur dioxide. Understanding these changes helps us grasp how energy is released and new compounds are formed during chemical reactions.

Phosphorus Compound

Phosphorus compounds are essential in various chemical reactions and everyday products. Phosphorus sesquisulfide, with the formula \(P_4S_3\), is one such compound. Phosphorus sesquisulfide is notable for its use in ‘strike anywhere’ matches, where it serves a critical role in the ignition process.

• The compound is a yellow to grayish powder with another important property: high reactivity with oxygen.
• It is the phosphorus compound that ignites upon friction, making it practical for match stick heads.

Insights into phosphorus sesquisulfide's characteristics and reactions contribute to broader knowledge of phosphorus chemistry.

Balanced Chemical Equation

A balanced chemical equation is fundamental for accurately representing a chemical process. It ensures that the same number of each type of atom appears on both the reactant and product sides of the equation. Balancing equations involves counting atoms and adjusting coefficients to match the reactants to the products numerically. In the balanced equation: \[P_4S_3 + 8O_2 \rightarrow P_4O_{10} + 3SO_2\]the stoichiometric coefficients show:

• 1 molecule of \(P_4S_3\) (phosphorus sesquisulfide)
• 8 molecules of \(O_2\) (oxygen)
• producing 1 molecule of \(P_4O_{10}\) (phosphorus pentoxide)
• and 3 molecules of \(SO_2\) (sulfur dioxide).

Understanding balanced chemical equations is vital for accurately studying chemical reactions and their corresponding changes.