Problem 61 - Chemistry

Question

Write formulas for the following molecular compounds: (a) Disulfur dichloride (b) Iodine monochloride (c) Nitrogen triiodide (d) Dichlorine monoxide (e) Chlorine trioxide (f) Tetrasulfur tetranitride

Step-by-Step Solution

Answer

S2Cl2, ICl, NI3, Cl2O, ClO3, S4N4.

Step 1: Understanding Molecular Compound Naming

Molecular compounds are named using prefixes that indicate the number of atoms present. The prefixes are: mono- (1), di- (2), tri- (3), tetra- (4), penta- (5), hexa- (6), hepta- (7), octa- (8), nona- (9), and deca- (10). The first element in the compound name keeps its full naming form, while the second element is typically altered to end in '-ide'.

Step 2: Identifying Names and Matching Prefixes

For each compound, identify the elements present and use the prefixes in the name to determine how many of each atom are in the formula. For example, 'disulfur dichloride' uses the prefix 'di-' for both elements, indicating there are 2 sulfur atoms and 2 chlorine atoms.

Step 3: Writing the Formula for Disulfur Dichloride

Disulfur dichloride: The prefix 'di-' indicates 2 atoms of each element. Therefore, the formula is \( \text{S}_2\text{Cl}_2 \).

Step 4: Writing the Formula for Iodine Monochloride

Iodine monochloride: The prefix 'mono-' indicates 1 chlorine atom. Therefore, the formula is \( \text{ICl} \).

Step 5: Writing the Formula for Nitrogen Triiodide

Nitrogen triiodide: The prefix 'tri-' indicates 3 iodine atoms. Therefore, the formula is \( \text{NI}_3 \).

Step 6: Writing the Formula for Dichlorine Monoxide

Dichlorine monoxide: The prefix 'di-' indicates 2 chlorine atoms, and 'mono-' indicates 1 oxygen atom. Thus, the formula is \( \text{Cl}_2\text{O} \).

Step 7: Writing the Formula for Chlorine Trioxide

Chlorine trioxide: The prefix 'tri-' indicates 3 oxygen atoms. Therefore, the formula is \( \text{ClO}_3 \).

Step 8: Writing the Formula for Tetrasulfur Tetranitride

Tetrasulfur tetranitride: The prefix 'tetra-' indicates 4 atoms of each element. Therefore, the formula is \( \text{S}_4\text{N}_4 \).

Key Concepts

Naming Molecular Compounds

When we talk about naming molecular compounds, we're referring to the practice of identifying chemical compounds composed of non-metal elements. This process is essential in chemistry as it allows us to understand what the compound is made from and thus, predict its properties and reactions.
Molecular compounds follow a set naming convention where the first element is given its full name. For example, in 'carbon monoxide', 'carbon' is the first element and is named as is.
The second element, on the other hand, gets a suffix added to its name, usually '-ide'.

• Carbon dioxide (CO₂)
• Sulfur dioxide (SO₂)

This systematic approach removes ambiguity and makes communication about compounds much clearer between scientists.

Chemical Prefixes

Chemical prefixes are adjectives used in chemistry to denote the quantity of atoms of an element present in a molecular compound. These prefixes tell you the number of atoms involved without having to look at the chemical formula itself.

• Mono- (1)
• Di- (2)
• Tri- (3)
• Tetra- (4)
• Penta- (5)
• Hexa- (6)

For example, the name "dioxide" in a molecule like carbon dioxide (CO₂) tells us there are two oxygen atoms. Chemical prefixes help streamline the naming procedure and make sure no two compounds are mistaken for each other, even if they contain similar elements.

Binary Compounds

Binary compounds are chemical compounds consisting of two different elements. Understanding these compounds is fundamental for anyone studying chemistry.
These compounds often consist of a metal and a non-metal, or two non-metals, combining in various ways. In molecular compounds where non-metals are involved, prefixes are used to indicate the number of atoms. For instance:

• Sulfur dichloride (S₂Cl₂)
• Nitrogen dioxide (NO₂)

In binary compounds, clarity in communication is key. The naming system aligns with chemical nomenclature standards so that anyone familiar with chemistry can understand and replicate the work.

Chemical Nomenclature

Chemical nomenclature is a set of rules and principles that chemists use to name substances in a consistent way. This naming system is standardized and governed by the International Union of Pure and Applied Chemistry (IUPAC).
With chemical nomenclature, each compound has a unique name, which prevents confusion.

• The use of prefixes gives insight into the molecule's bonding.
• The suffix '-ide' often indicates the presence of a single type of anion.

For example, hydrogen chloride (HCl) in gaseous form becomes hydrochloric acid when dissolved in water, illustrating how naming changes can reflect different states or contexts. Understanding these rules allows scientists to effectively share findings and ensure precise communication about chemical compounds across global scientific communities.