Lecture 1 - Introduction to Organic Chemistry

Question 1

molecule composition:

Answer 1

molecules are composed of discrete collections of atomic nuclei and electrons held together by force

Question 2

atomic connectivity:

Answer 2

how atoms in a molecule are connected also known as a molecules “constitution”

Question 3

molecular geometry:

Answer 3

how far apart atoms are and how they are arranged in space

Question 4

knowing atomic connectivity and molecular geometry reveals…

Answer 4

… molecular structure

Question 5

chemical reaction theory:

Answer 5

a chemical reaction occurs when there is a reorganisation of the electrons and bonds

Question 6

bond length:

Answer 6

distance between nuclei

Question 7

bond angle:

Answer 7

angle between each pair of bonds

Question 8

bond length changes:

Answer 8

• bond length increases with atoms down a group
• bond length decreases with increasing bond order
• bond length decreases toward higher atomic number along a row (period)

Question 9

bond angles:

Answer 9

bond angles determine the molecular shape and are controlled by valence-shell electron-pair repulsion (VSEPR)

Question 10

common molecular shapes and their electron composition:

Answer 10

linear: two outer atoms with no lone pairs

triagonal planar: three outer atoms with no lone pairs

trigonal pyramidal: three outer atoms with one lone pair

tetrahedral: four outer atoms with no lone pairs