Problem 17 - Chemistry Matter and Change

Question

Name each of the binary covalent compounds listed below. $$\mathrm{CCl}_{4}$$

Step-by-Step Solution

Answer

The compound \( \mathrm{CCl}_{4} \) is named 'Carbon Tetrachloride'.

Step 1: Understanding Binary Covalent Compounds

Binary covalent compounds are composed of two different non-metal elements. The number of atoms of each element in the molecule is indicated using prefixes. For example, 'mono-' for one, 'di-' for two, 'tri-' for three, and so on.

Step 2: Identifying the Elements

The formula given is \( \mathrm{CCl}_{4} \). It consists of two elements: Carbon (C) and Chlorine (Cl). Carbon is written first and is the central atom, followed by Chlorine.

Step 3: Prefix Determination for Carbon

Since there is only one carbon atom and it is the first element, traditionally when naming binary covalent compounds, we do not use the 'mono-' prefix for the first element. Thus, we simply write 'Carbon'.

Step 4: Prefix Determination for Chlorine

There are four chlorine atoms present, which is indicated by the subscript '4'. The prefix for 'four' is 'tetra-', so we name the chlorine part as 'tetrachloride'.

Step 5: Combining the Names

Combine the names obtained from the previous steps: 'Carbon' (for carbon) and 'Tetrachloride' (for chlorine with 4 atoms). Thus, the compound \( \mathrm{CCl}_{4} \) is named 'Carbon Tetrachloride'.

Key Concepts

Prefixes in Chemistry

In chemistry, prefixes are essential when it comes to naming binary covalent compounds. These prefixes indicate the number of atoms of each element present in a compound. Understanding these prefixes can greatly aid in deciphering chemical formulas.

Here are some commonly used prefixes:

• Mono-: This prefix denotes the presence of one atom. However, it's typically omitted for the first element.
• Di-: This indicates two atoms of an element are present.
• Tri-: Used when there are three atoms.
• Tetra-: Signifies that there are four atoms present.
• Penta-: This prefix denotes five atoms.

These prefixes are not only helpful for naming purposes but also play a crucial role in conveying accurate chemical information through the compound’s name.

Chemical Formula Interpretation

Interpreting chemical formulas is fundamental in understanding covalent compounds. Each chemical formula tells us exactly which elements are present and how many atoms of each you can find in the compound.

The formula for our example is \( \mathrm{CCl}_{4} \). This translates to:

• \(\mathrm{C}\): Carbon is one element; it appears once.
• \(\mathrm{Cl}_{4}\): Chlorine is another element; it appears four times.

The subscript numbers indicate the number of atoms present for the element they follow. If no subscript is present, it means there is only one atom of that element. This concise representation is crucial for scientists and students alike when predicting the nature or behavior of compounds.

Carbon Tetrachloride Naming

The name 'Carbon Tetrachloride' follows the conventions for naming binary covalent compounds, reflecting the number and type of atoms present. The process begins by identifying each element in the formula and the number of atoms present.

Once identified:

• Carbon: Since there is only one atom of carbon, we do not use the 'mono-' prefix. It remains simply 'Carbon'.
• Chlorine: There are four chlorine atoms, hence the prefix 'tetra-' is attached. Adding 'chloride' (the root name for chlorine) results in 'Tetrachloride'.

Bringing these parts together forms the name 'Carbon Tetrachloride' for \(\mathrm{CCl}_{4}\). This systematic approach ensures clarity in scientific communication.

Covalent Compound Naming Rules

The naming of covalent compounds can be simplified by following a few standard rules. These rules ensure that each compound is named consistently and clearly:

1. **Name the elements in order**: The element with the positive oxidation state (less electronegative) is usually listed first. For \(\mathrm{CCl}_{4}\), carbon comes before chlorine.

2. **Prefix application**: Even if it's less common to use 'mono-' for the first element, always use proper prefixes for the second element. This indicates the number of atoms.

3. **Ending with '-ide'**: The name of the second element is modified to end with '-ide'. In \(\mathrm{CCl}_{4}\), 'chlorine' changes to 'chloride'.

Using these rules, scientists and students can derive the names and implications of various binary covalent compounds. Once these basic steps and rules are learned, naming becomes a straightforward task.