1. Introduction to organic chemistry

Multiple Choice

Which two elements do all organic compounds contain?

• Carbon and hydrogen

• Carbon and oxygen

• Oxygen and hydrogen

• Carbon and nitrogen

Multiple Choice

Which type of bonding is present within organic molecules?

• Covalent bond

• Ionic bond

• Metallic bond

• Hydrogen bond

Multiple Choice

There are millions of compounds in organic chemistry due to the bonding capacity of ..................element

• Oxygen

• Carbon

• Hydrogen

• Nitrogen

Multiple Choice

Which statement is correct?

• All organic compounds contain carbon

• All organic compounds contain hydrogen

Multiple Choice

Organic reactions are generally very ......................and .......................are needed

• fast - inhibitor

• slow -catalyst

• fast - catalyst

• slow - inhibitor

Multiple Choice

Using combustion reaction of an organic compound, the empirical formula of the compound is found as CH₂O . If the molar mass of organic compound is 180g/mol what is the molecular formula of the compound ? (C:12g/mol, H:1g/mol, O:16g/mol)

• C₁₂H₂₄O₁₂
• C₈H₁₆O₈
• C₆H₁₂O₆
• C₃H₆O₃

​Drawing skeletal structures

Lewis structures show every atom and bond, which is impractical for large molecules. To simplify, chemists use bond-line structures. Bond-line structures focus on C–C bonds and bonds to heteroatoms (O, N, S, P). Carbons are not drawn, while heteroatoms are shown.

​Full Lewis: shows all atoms and bonds.
Condensed Lewis: shows all atoms, but some bonds are omitted.
Bond-line: simplest form, uses lines to represent molecules while still giving the same information.

​Quick Steps to Draw Bond-Line Structures:
1. Identify the carbon chain: Focus on the longest continuous chain of carbon atoms.
2. Use zig-zag lines: Each vertex or line end represents a carbon atom.
3. Show bonds: Lines represent C–C or C–heteroatom bonds. Triple bonds are straight.
4. Add heteroatoms: Always draw atoms like O, N, S, P; hydrogens on carbons are implied.
5. Place substituents properly: Attach side groups at the correct position on the main chain.
6. Check geometry: Ensure bond angles roughly reflect tetrahedral, trigonal, or linear geometry.

Multiple Choice

What is a functional group?

• Atoms or group of atoms that give specific characteristics to a molecule

• Group of molecules that make up a group of atoms

• Group of molecules that give specific characteristics to an atom

• Group of atoms that give specific characteristics to an element

Multiple Choice

How many hydrogens are missing from this extended structural formula?

• 6

• 7

• 8

• 9

Multiple Choice

What is the condensed formula of this structure?

• CH₃CH₂CH₂OH

• CH₃COCH₃

• CH₃CH₂CHO

• CH₃OCH₂CH₃

Multiple Choice

What is the condensed formula of this structure?

• CH₃CH₂CH₂OH

• CH₃COCH₃

• CH₃CH₂CHO

• CH₃OCH₂CH₃

Multiple Choice

The given structure is an example of ...

• Expanded structure

• Condensed structure

• Skeletal structure

Multiple Select

If the given structure is converted to condensed structure, which will be its correct version?

• CH₃CH₂CH₂CH₂CH₂CH₃

• CH₃(CH₂)₄CH₃

• C₆H₁₄

• (CH₃)₂(CH₂)₄

Multiple Choice

What is the molecular formula for structure showed?

• C₈H₁₈

• C₃H₃

• C₈H₃

• C₃H₂(CH₃)₃

Multiple Choice

Carbon has _____ valence electrons.

• 2

• 4

• 6

• 8

Multiple Choice

Which of the two is an Organic Compound?

Multiple Choice

Which type of formulas represents only combination ratio of the constituent atoms?

• Structural Formula
• Empirical Formula
• Molecular Formula
• Condense Formula

Multiple Choice

Which of the following compounds is not organic?

• CH₄
• CO
• C₂H₂
• CCl₄