Question

Radioastronomers have detected the isoformyl ion, \(\mathrm{HCO}^{\top}\), in outer space. Write the Lewis structure for this ion.

Short answer

Answer: The Lewis structure for the isoformyl ion, HCO+, is H-C=O with two lone pairs on the oxygen atom.

Step-by-step solution

Count the valence electrons

First, we have to determine the total number of valence electrons in the isoformyl ion, HCO+: Hydrogen (H) has 1 valence electron, Carbon (C) has 4 valence electrons, Oxygen (O) has 6 valence electrons, and there is a +1 charge, which means we have to subtract 1 electron. Adding all the electrons, we have: \(1 + 4 + 6 - 1 = 10\) valence electrons.

Arrange the atoms

We arrange the atoms and create the basic molecule structure. Here, carbon is typically the central atom due to its affinity for bonding, and we place hydrogen and oxygen atoms around the central carbon atom: H-C-O.

Distribute the valence electrons

Now we need to share the valence electrons among the atoms to satisfy their octet (or duet for hydrogen). Starting with the H-C bond, assign 2 electrons to create a single bond. Assign remaining electrons to the oxygen atom to complete its octet: - Add 4 electrons to the O (two lone pairs) to give the oxygen six electrons. - Next, share 2 electrons between the C and O atom to create a double bond.

Check extra electrons

Check if there are any extra electrons left to distribute. In this case, we've used all 10 valence electrons. Now you have the Lewis structure for the isoformyl ion, \(\mathrm{HCO}^{\top}\): H-C=O with two lone pairs on the oxygen atom.

Key concepts

Valence Electrons

Valence electrons are the electrons found in the outermost shell of an atom. They play a crucial role in forming chemical bonds. Understanding how many valence electrons an atom has can help predict how it will bond with other atoms.

• Hydrogen (H) has 1 valence electron.
• Carbon (C) has 4 valence electrons.
• Oxygen (O) has 6 valence electrons.

Together, these electrons contribute to the molecule's structure and reactivity. When dealing with ions, you also need to account for any charge—which either adds or subtracts electrons to maintain electrical neutrality. In the case of the isoformyl ion, \(\mathrm{HCO}^{+}\), the +1 charge means you subtract 1 electron, resulting in a total of 10 valence electrons. Properly counting and allocating these electrons is crucial for drawing the correct Lewis structure.

Isoformyl Ion

The isoformyl ion is a fascinating species detected in outer space, known chemically as \(\mathrm{HCO}^{+}\). To understand this ion, we must consider its components: hydrogen, carbon, and oxygen, along with its positive charge.

• Hydrogen usually forms one bond as it only needs a duet (two electrons) to complete its stable electron configuration.
• Carbon acts as the central atom. It's typical in organic chemistry because of its ability to form four bonds, due to having four valence electrons.
• Oxygen is more electronegative and typically forms stronger bonds, such as double bonds, to complete its octet requirement.

When arranging the atoms, the structure will typically place carbon in the center with hydrogen on one end and oxygen on the other. The positive charge in the isoformyl ion signifies a deficit of one electron, which influences how electrons are shared among atoms and ultimately affects the ion's stability and reactivity.

Octet Rule

The octet rule is an important principle in chemistry that suggests atoms are most stable when they have eight electrons in their valence shell. This rule explains why atoms tend to form bonds and how electrons are distributed in molecules.

• Hydrogen is an exception as it only requires two electrons to achieve stability, forming a 'duet'.
• Carbon and Oxygen in the isoformyl ion seek to satisfy the octet rule. Carbon utilizes four valence electrons, enabling it to form four bonds, while oxygen uses its six valence electrons and typically forms two bonds to fill its valence shell.

During bonding, atoms share, gain, or lose electrons to fulfill the octet rule. In \(\mathrm{HCO}^{+}\), the formation of a carbon-oxygen double bond helps ensure that both carbon and oxygen are as close as possible to having eight valence electrons. This arrangement provides optimal stability and electron configuration for the molecule.