Questions: Carbon tetrachloride (CBr4) is a crystalline solid that has a density much higher than water. What is the electron geometry and molecular geometry for the central atom in carbon tetrachloride?

Carbon tetrachloride (CBr4) is a crystalline solid that has a density much higher than water. What is the electron geometry and molecular geometry for the central atom in carbon tetrachloride?

Transcript text: Carbon tetrabromide $\left(\mathrm{CBr}_{4}\right)$ is a crystalline solid that has a density much higher than water. What is the electron geometry and molecular geometry for the central atom in carbon tetrabromide? Both the electron and molecular geometries are tetrahedral. The electron geometry is tetrahedral, and the molecular geometry is trigonal planar. The electron geometry is tetrahedral, and the molecular geometry is trigonal pyramidal. Both the electron and molecular geometries are trigonal pyramidal.

Solution

Solution Steps

Step 1: Determine the Lewis Structure of Carbon Tetrabromide

Carbon tetrabromide ($\text{CBr}_4$) consists of one carbon atom bonded to four bromine atoms. Carbon has four valence electrons, and each bromine has seven valence electrons. The total number of valence electrons is $4 + 4 \times 7 = 32$.

Step 2: Identify the Electron Geometry

The central carbon atom forms four single bonds with the four bromine atoms. According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, the electron pairs around the central atom will arrange themselves to minimize repulsion. With four bonding pairs and no lone pairs, the electron geometry is tetrahedral.

Step 3: Determine the Molecular Geometry

Since there are no lone pairs on the central carbon atom and it is bonded to four bromine atoms, the molecular geometry is also tetrahedral. The shape is determined by the positions of the atoms, which in this case, align with the electron geometry.