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.
1. Determine if the following compounds are polar, non-polar or ionic molecules?
- CCl4
- BF3
- NH3
- CBr4
- N2
- H2S
- H2O
- CH3
- H2
3. Which of the properties listed here are characteristic of an ionic bond?
- low melting point
- good electricity conductor as a solid
- dissolves in water to form a solution that contains mostly ions
- dissolves to form a solution that contains mostly molecules
- good electricity conductor when melted
- forms solid crystals
- i,iii,iv
- ii,v,vi
- iii,v,vi
- ii,iii,v
- i,iii,vi
4. What type of intermolecular force is found between:
- F2
- Cl2
- water molecules?
5. Which ONE of the following substances is LEAST ionic (hint calculate each bond)?
- NaCl
- KCl
- CuCl2
- SbCl4
6. Calculate the difference in electronegativity (ΔEN) for the bonds that would form between the groups of atoms listed below. State whether the bond would be ionic, polar covalent or non-polar covalent.
- N and Cl
- B and Br
- B and F
- Al and O
- N and F
- C and H
- Mg and I
- Li and S
- C and F
- Na and N
7. Explain why HBr is a polar molecule, but H2 and Br2 are not.
8.Predict what type of solid will be formed in each of the following:
- boron and nitrogen
- francium and iodine
- carbon and sulphur
- silicon dioxide (quartz)
- copper sulphate and zinc
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
