Formal Charges
Formal charges have an important role in organic chemistry since this concept helps us to know whether an atom in a molecule is neutral/bears a positive or negative charge. Even if some molecules are neutral, the atoms within that molecule need not be neutral atoms.
Polarity Of Water
In simple chemical terms, polarity refers to the separation of charges in a chemical species leading into formation of two polar ends which are positively charged end and negatively charged end. Polarity in any molecule occurs due to the differences in the electronegativities of the bonded atoms. Water, as we all know has two hydrogen atoms bonded to an oxygen atom. As oxygen is more electronegative than hydrogen thus, there exists polarity in the bonds which is why water is known as a polar solvent.
Valence Bond Theory Vbt
Valence bond theory (VBT) in simple terms explains how individual atomic orbitals with an unpaired electron each, come close to each other and overlap to form a molecular orbital giving a covalent bond. It gives a quantum mechanical approach to the formation of covalent bonds with the help of wavefunctions using attractive and repulsive energies when two atoms are brought from infinity to their internuclear distance.
![### Construct the Molecular Orbital Diagram for \( He_2 \)
To construct the molecular orbital (MO) diagram for the diatomic helium molecule \( He_2 \), follow these steps:
#### Diagram Explanation
- **Atomic Orbitals (AOs) from Each Helium Atom:**
- Each helium atom \( He \) contributes one \( 1s \) atomic orbital, represented at each side of the diagram.
- These \( 1s \) orbitals are shown as squares labeled "1s" on both the left and right sides of the diagram.
- **Molecular Orbitals (MOs):**
- When combining the two \( 1s \) atomic orbitals from each helium atom, two molecular orbitals are formed: a bonding orbital (\( \sigma_{1s} \)) and an antibonding orbital (\( \sigma^*_{1s} \)).
- The bonding orbital (\( \sigma_{1s} \)) is at a lower energy level and is represented at the bottom center of the diagram.
- The antibonding orbital (\( \sigma^*_{1s} \)) is at a higher energy level and is represented at the top center of the diagram.
- The electron configuration is represented using boxes and arrows to show the electrons. He atom (1s²) will have two electrons represented by opposite-facing arrows in the box.
- **Electron Placement:**
- Follow the given placeholders (dashed squares) for electrons in the molecular orbitals.
- The Answer Bank provides arrows indicating electron spin. One shows a single upward arrow and the other a pair of arrows (one up and one down).
#### Bond Order Calculation
- **Identify the Bond Order:**
- Bond order is calculated using the formula:
\[
\text{Bond Order} = \frac{(N_b - N_a)}{2}
\]
where \( N_b \) is the number of electrons in bonding orbitals and \( N_a \) is the number of electrons in antibonding orbitals.
- For \( He_2 \), the electrons in \( \sigma_{1s} \) and \( \sigma^*_{1s} \) need to be summed up to identify the corresponding bond order.
Lastly, you can select the bond order from the given options:
- \( \circ \) 0
- \(](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F3e3f76e7-3e2b-4631-a85d-ebd3274410fe%2F979d4b1e-e7d8-4b59-ac43-6a2f144e20a4%2Fdr16kwj_processed.png&w=3840&q=75)
Step by step
Solved in 3 steps with 8 images
