Problem 28 - Chemistry: Principles and Reactions

Question

Give the number of protons and electrons in (a) a \(\mathrm{C}_{60}\) molecule. (b) a CN- ion. (c) a \(\mathrm{CO}_{2}\) molecule. (d) an \(\mathrm{N}^{3-}\) ion.

Step-by-Step Solution

Answer

To summarize: (a) A C60 molecule has 360 protons and 360 electrons. (b) A CN- ion has 13 protons and 14 electrons. (c) A CO2 molecule has 22 protons and 22 electrons. (d) An N3- ion has 7 protons and 10 electrons.

Step 1: (a) Calculate the proton and electron count in a \(\mathrm{C}_{60}\) molecule.

A \(\mathrm{C}_{60}\) molecule consists of 60 carbon atoms. The atomic number of carbon is 6, which means that each carbon atom has 6 protons. Therefore, the total number of protons in the molecule is \(60 \times 6 = 360\). Since it is a neutral molecule, the number of electrons is also 360.

Step 2: (b) Calculate the proton and electron count in a CN- ion.

The CN- ion consists of one carbon and one nitrogen atom. The atomic number of carbon is 6, and for nitrogen, it is 7. Therefore, the total number of protons in the ion is \(6 + 7 = 13\). Since the ion has a negative charge, it means there is one extra electron compared to a neutral molecule. Therefore, the total number of electrons is \(13 + 1= 14\).

Step 3: (c) Calculate the proton and electron count in a \(\mathrm{CO}_{2}\) molecule.

A \(\mathrm{CO}_{2}\) molecule consists of one carbon and two oxygen atoms. The atomic number of carbon is 6, and for oxygen, it is 8. The total number of protons in the molecule is \(6 + 2(8) = 22\). As it is a neutral molecule, the number of electrons is also 22.

Step 4: (d) Calculate the proton and electron count in an \(\mathrm{N}^{3-}\) ion.

The \(\mathrm{N}^{3-}\) ion is an ion of nitrogen with three extra electrons. The atomic number of nitrogen is 7, which means it has 7 protons. Considering the three extra electrons, the electron count is \(7 + 3 = 10\).

Key Concepts

C60 molecule

The omenclature "C60" refers to a molecule made of 60 carbon atoms arranged in a structure resembling a soccer ball, also known as buckminsterfullerene. As with any carbon atom, the atomic number is 6, reflecting the number of protons in its nucleus. Thus, in this molecule, the total proton count is obtained by multiplying the atomic number by the number of carbon atoms:

• Protons: 60 carbon atoms × 6 protons per atom = 360 protons
• Electrons: Since it is a neutral molecule, the electron count is equal to the proton count, meaning there are also 360 electrons.

Being composed solely of carbon, the distinctive spherical structure contributes to its stability, making it an interesting subject in nanotechnology.

CN- ion

The CN^- ion, or cyanide ion, comprises one carbon atom and one nitrogen atom. It is known for its strong, linear bond between carbon and nitrogen. To determine the proton count, consider:

• Carbon's atomic number is 6, giving 6 protons.
• Nitrogen's atomic number is 7, contributing 7 protons.
• Thus, total protons: 6 + 7 = 13 protons.

The CN^- ion has a negative charge, indicating an extra electron, bringing the total electron count to:

• Total electrons: 13 (from protons) + 1 (extra) = 14 electrons.

This ion's chemistry is significant in many biological and industrial processes due to its reactivity.

CO2 molecule

The chemical formula CO₂ represents a molecule made of one carbon and two oxygen atoms, forming a linear shape. In order to calculate protons and electrons:

• Carbon's atomic number (6) gives 6 protons.
• Oxygen's atomic number is 8, thus 2 oxygen atoms contribute 2 × 8 = 16 protons.
• Total protons: 6 (carbon) + 16 (oxygen) = 22 protons.

For a neutral CO₂ molecule, the electron count equals the proton count. Therefore, there are also 22 electrons in the molecule.

• Electrons: 22 electrons

This molecule is well known for its role in the greenhouse effect and is a critical compound in many biological processes, including respiration and photosynthesis.

N3- ion

The N^3- ion represents a nitrogen atom that has gained three additional electrons, resulting in a trinegative charge. Calculating the proton and electron counts involves:

• Nitrogen's atomic number is 7, providing 7 protons.
• Since the ion has gained three extra electrons, we account for these in the total electron count.
• Total electrons: 7 (from protons) + 3 (extra) = 10 electrons.

The N^3- ion is commonly encountered in the context of its use in various chemical reactions, particularly in the formation of ionic compounds.