Question

Q3/ (15 Marks) Explain the following: 1. Alkene stability. 2. Isomerism structural. 3. Molecular Orbitals of Carbon-Carbon. 4. Inductive Effects.

Answer 1

1. ALKENE STABILITY

• With Increase in Substitution, the stabilty of the Alkene also increases.
• The stability of the alkene measured by the amount of heat energy associated with hydrogenation of the molecules.
• When there is higher the stability of the alkenes , there is lower the heat of hydrogenation.
• According to the stability of Alkene ,Due to steric hindrance, the trans isomers are more stable than cis isomers
• Due to hypercojugation, the more substituted alkenes are more stable as compare to less substituted alkenes.
• The substituents of alkenes arranged in cis configuartion of double bond is less stable than the substituents of alkenes arranged in trans configuration of same side.
• For example a tri substituted alkene is more stable than a tetra substituted alkene.

2. ISOMERISM STRUCTURAL

• Structural isomerism have same molecular formula but different in their strutural formula
• The structural isomers refers to the compounds which are differ in their connectivity between the atoms that consist that compounds.
• Stereoisomers are the compound having same connectivity and molecules but different in their arrangement of atoms in three diminesion space.
• Structural isomerism does not have same chemical behaviour.
• Two same structural isomerism have diferent in boiling points.
• The structural isomerism have same atom number as well as same atomic weight.
• For example isobutane(C₄H₁₀) and butane are stuctural isomerism with each other.

3. MOLECULAR ORBITAL OF CARBON CARBON ATOMS

• Carbon carbon bond is the type of co-valent bond between the two carbon atoms.
• Single bond is comprises of two electrons by the sharing of two atoms.
• The carbon carbon single bond refers to the sigma bond which is formed between the one hybridized orbital from each of the carbon atoms.
• The carbon atom in single bond, there is no necessary of the same hybridization.
• Carbon atoms forms double bond as well as triple bond in which double bond compounds are known as Alkenes and triple bond compound known as Alkynes.
• A double bond of carbon atom formed with an p-orbital and sp²-hybridized orbital and a triple bond of carbon atom formed with an two p-orbitals and sp-hybridized orbital.
• The main use of the pi-orbitals is to form pi-bonds.
• Example
• 
  Example: 1) methane (chey) O → 4 (15 bitan) (sporebital) 888 s orebital se onbitan) (IL 7L (sp Hybridisation 12 С It H H (me thane (CHA) (W1 atom
  

4. INDUCTIVE EFFECTS

• Inductive effect is the type of effect which refers to the transmission of unequal sharing of bonding electron through a chain of atoms in a molecule directing to a permanent dipole in a bond.
• Inductive effect is the effect on electron density in one part of the molecule due to the presence of electron donating and withdrawing groups in molecules.
• The inductive effect appears in sigma($\sigma$) bond and the electromeric effect appears in pi($\pi$) bond.
• In inductive effect the sigma electron displacement towards the highly electronegative atoms by which in one part is negatively charged and othe part is positevly charged.
• Inductive effect also plays an important role to determine the stability of the molecules. That means if an atoms has Positive Charge and connect to a -I group , then the molecule become unstable.And If the atoms has a negative charge and it connect to a -I group then the molecule consider as Stable.
• for example,properties of alkyl and carboxylic group.