Problem 91 - Chemistry Matter and Change

Question

Watches The quartz crystals used in watches are made of silicon dioxide. Explain how you use the name to determine the formula for silicon dioxide.

Step-by-Step Solution

Answer

The formula for silicon dioxide is SiO₂, with one silicon atom and two oxygen atoms.

Step 1: Identify Components from Name

The name 'silicon dioxide' provides us with important information about the compound's composition. The first part 'silicon' indicates the presence of silicon atoms, and the second part 'dioxide' suggests the presence of oxygen atoms in a specific ratio to the silicon.

Step 2: Analyze the Suffix '-dioxide'

The suffix 'dioxide' signifies that there is a ratio of two oxygen atoms for every other element in the compound. The 'di-' prefix specifically means two oxygen atoms.

Step 3: Combine Elements with Correct Ratios

With the understanding that 'silicon' contributes one silicon atom and 'dioxide' indicates two oxygen atoms, we can write the chemical formula by combining these in the given ratio. Therefore, one silicon atom (Si) combines with two oxygen atoms (O) to form the compound SiO₂.

Key Concepts

Silicon Dioxide

Silicon dioxide, often referred to as silica, is a compound that consists of silicon and oxygen. It is one of the most abundant minerals on Earth, commonly found in sand and quartz. The chemical formula for silicon dioxide is SiO₂. This means that for every silicon atom, there are two oxygen atoms bonded to it.
Understanding the nature of silicon dioxide helps us comprehend its wide usage in industries, including electronics, where it is used in products such as watches. Since it is a key material for making quartz crystals in watches, its composition directly impacts the operational efficiency of these timekeeping devices.
Silica’s ability to vibrate at a steady frequency when an electric current is applied makes it crucial in keeping accurate time, which is why silicon dioxide is so important in the world of wristwatches.

Molecular Composition

The molecular composition of a compound indicates what atoms are present and in what proportion. For silicon dioxide, the composition includes silicon and oxygen atoms. This can be figured out from its chemical formula, SiO₂.
In this case, 'Si' stands for silicon, while 'O' stands for oxygen. The subscript '2' following the 'O' hints at how many oxygen atoms are in the molecule. Thus, the formula SiO₂ shows that there are two oxygen atoms for each silicon atom, which is the critical aspect of its composition.

• A single silicon atom bonded with two oxygen atoms gives silicon dioxide its structure.
• This 1:2 ratio is what determines many of the material's physical and chemical properties.

Such tight bonding between silicon and oxygen makes silicon dioxide a stable and incredibly durable compound.

Chemical Nomenclature

Chemical nomenclature is the system for naming chemical substances through a set of established rules. It allows scientists and chemists to communicate about specific compounds easily. Silicon dioxide, for instance, is named according to its elements and their quantities.
The name 'silicon dioxide' gives explicit clues about its composition: 'silicon' refers to the silicon atom present, while 'dioxide' indicates two oxygen atoms. The root 'di-' is a prefix used in chemical nomenclature to denote the number two.

• The nomenclature provides insight into the compound’s structure: one silicon atom bonded with two oxygen atoms.
• Knowing these naming conventions can help predict the composition of other similar compounds.

Understanding chemical nomenclature is crucial as it forms the basis of identifying compounds and effectively communicating their uniqueness in scientific discussions.