Problem 60 - General Chemistry: Principles and Modern Applications

Question

Assign suitable names to the compounds (a) ICl; (b) \(\mathrm{ClF}_{3} ;\) (c) \(\mathrm{SF}_{4} ;\) (d) \(\mathrm{Br} \mathrm{F}_{5} ;\) (e) \(\mathrm{N}_{2} \mathrm{O}_{4} ;\) (f) \(\mathrm{S}_{4} \mathrm{N}_{4}\).

Step-by-Step Solution

Answer

(a) Iodine monochloride; (b) Chlorine trifluoride; (c) Sulfur tetrafluoride; (d) Bromine pentafluoride; (e) Dinitrogen tetroxide; (f) Tetrasulfur tetranitride.

Step 1: Naming Binary Compounds Consisting of Two Nonmetals

For binary compounds, the element with the lower group number is written first in the name; if the elements are in the same group, the element with the higher period number is written first. The second element is named as though it were an anion. So, compound (a) ICl is named as Iodine monochloride.

Step 2: Naming Compounds with More than Two Nonmetals

For compounds with more than two nonmetals, we use the prefixes mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, and deca- to denote the number of atoms of each element. Compound (b) \(\mathrm{ClF}_{3}\) is therefore Chlorine trifluoride, compound (c) \(\mathrm{SF}_{4}\) is Sulfur tetrafluoride, and compound (d) \(\mathrm{BrF}_{5}\) is Bromine pentafluoride.

Step 3: Naming Binary Compounds with Subscripts

For binary compounds with a subscript on both elements, apply the same rules as in step 2. Therefore, compound (e) \(\mathrm{N}_{2}\mathrm{O}_{4}\) is Dinitrogen tetroxide, and compound (f) \(\mathrm{S}_{4}\mathrm{N}_{4}\) is Tetrasulfur tetranitride.

Key Concepts

Binary Compounds

Binary compounds are made from two different elements. In chemistry, the naming of these compounds follows a systematic method to make it clear what atoms are present. Usually, binary compounds consist of two nonmetals. Examples include compounds like ICl, ClF\(_3\), or SF\(_4\). Here, each compound contains only two different kinds of atoms.
When naming binary compounds, the element appearing first is typically the one that is closest to the left on the periodic table. If they're in the same column, the element that is lower is named first. For instance, in ICl (Iodine monochloride), iodine is placed ahead of chlorine because of positioning rules in the periodic table.
The second element in a binary compound is named as if it were an anion, which means its name often ends in '-ide'. This structured naming helps chemists easily communicate the presence of elements in a compound.

Prefixes in Chemistry

When working with chemical compounds, especially those involving nonmetals, prefixes become important. They indicate the number of atoms present in a molecule. Here are the prefixes used most often:

• mono- (1)
• di- (2)
• tri- (3)
• tetra- (4)
• penta- (5)
• hexa- (6)
• hepta- (7)
• octa- (8)
• nona- (9)
• deca- (10)

Prefixes help in naming compounds like N\(_2\)O\(_4\), called dinitrogen tetroxide. Here, 'di-' means two nitrogen atoms and 'tetra-' means four oxygen atoms. This clear naming system is crucial, especially in complex chemical formulas.
Note that the prefix 'mono-' is often omitted when the first element has only one atom, as seen in ICl (Iodine monochloride), where 'mono-' is used only for the second element.

Nonmetals in Compounds

Nonmetals play a significant role in forming binary compounds. They typically appear in the upper right corner of the periodic table and include elements like oxygen, nitrogen, and sulfur.
In compounds, nonmetals tend to accept or share electrons, forming covalent bonds. This is why you often see them paired with each other, as in compounds such as SF\(_4\) (Sulfur tetrafluoride) or N\(_2\)O\(_4\) (Dinitrogen tetroxide).
Understanding how nonmetals pair with each other is key to mastering chemical nomenclature since these combinations are common in both natural and synthetic chemicals. Nonmetals can combine in different ways, forming various structures, and their reactivity impacts how compounds are named.