Question

The "Chemistry in Focus" segment Plastic That Talks and Listens! discusses polyvinylidene difluoride (PVDF). What is the empirical formula of PVDF? Note: An empirical formula is the simplest whole-number ratio of atoms in a compound. This is discussed more fully in Sections 8.7 and 8.8 of your text.

Short answer

The empirical formula of polyvinylidene difluoride (PVDF) is CHF.

Step-by-step solution

Identify the chemical formula of PVDF

The chemical formula of polyvinylidene difluoride (PVDF) is (C2H2F2)n, where 'n' is the number of repeating units.

Find the ratio of atoms in PVDF

In the chemical formula (C2H2F2)n, there are 2 Carbon atoms (C), 2 Hydrogen atoms (H), and 2 Fluorine atoms (F).

Simplify the ratio to the simplest whole-number ratio

The simplest whole-number ratio of atoms in PVDF (C2H2F2) is already in the simplest ratio as there are equal numbers of each respective atom.

Write the empirical formula

The empirical formula of PVDF (C2H2F2) is CHF. So, the empirical formula of polyvinylidene difluoride (PVDF) is CHF.

Key concepts

Polyvinylidene Difluoride

Polyvinylidene difluoride (PVDF) is a highly non-reactive and pure thermoplastic fluoropolymer. It is used in applications that require high resistance to solvents, acids, and bases. PVDF is known for its easy processing properties and its ability to be injected, molded, or welded.

One remarkable aspect of PVDF is its piezoelectric properties, meaning it can convert mechanical energy into electrical energy and vice versa. This characteristic makes it a popular choice for sensors and actuators in various electronic devices. Due to its unique properties, PVDF can be found in applications ranging from pipes and fittings in the chemical industry to films for solar panels.

Understanding the structure and chemical composition of PVDF helps students in the field of materials science and engineering to exploit its properties for innovative uses. Additionally, it is an excellent example of how the arrangement of molecules within a polymer can lead to a variety of practical and valuable properties.

Chemical Formula

The chemical formula of a substance is a representation of its molecular composition, showing the types and numbers of atoms that make up a single molecule of the substance. It is a fundamental concept in chemistry that allows chemists to communicate the composition of molecules succinctly and precisely.

When looking at the chemical formula of polyvinylidene difluoride, \(C_2H_2F_2\)n, it's important to note the use of subscripts to indicate the number of each type of atom in the polymer. The 'n' represents the number of repeating units, which signifies that PVDF is a polymer made up of many identical units linked together. The chemical formula is essential for calculating stoichiometry, understanding reactions, and exploring the properties of the material.

To fully grasp the concept of a chemical formula, it's instrumental to recognize the role of valency and bonding patterns among atoms, creating diverse structures and substances. This concept lays the groundwork for deciphering complex molecular structures and performing various calculations in any chemistry-related field.

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It is based on the conservation of mass, where the mass of the reactants equals the mass of the products. A stoichiometric calculation often involves converting between moles, mass, and the number of particles, using Avogadro's number and the molar mass of substances.

For compounds like PVDF with its empirical formula CHF, stoichiometry plays a crucial role in determining how much of each element is present in a given amount of the compound. It also helps in predicting the outcomes of chemical reactions, such as polymerization processes that synthesize PVDF. To solve stoichiometric problems, students need to understand concepts like the mole, molar mass, and Avogadro's number, as well as apply ratio and proportion mathematical techniques.

Stoichiometry is not just crucial for academic purposes but is also fundamental in industrial applications, such as determining the optimal amounts of raw materials required for production, and in environmental science, for calculating pollutant dispersal and concentration. It serves as the backbone for quantitative analysis in chemical research and applications.