Organic (U1)

Question 1

What are organic compounds?

Answer 1

Compounds that contain carbon and hydrogen. There are an infinite number of organic compounds.

Question 2

What is a homologous series?

Answer 2

A group of organic compounds with:
* The same functional group
* The same general formula
* Similar chemical properties
* A gradual change in physical properties
* A difference of CH2 between consecutive members

Question 3

What is a functional group?

Answer 3

An atom or group of atoms bonded in a specific arrangement that determines the chemical properties of a homologous series.

Question 4

How do you name organic compounds?

Answer 4

Prefix: Based on the number of carbon atoms (Meth-1, Eth-2, Prop-3, But-4, etc.)

Suffix:
* Alkane: -ane
* Alkene: -ene
* Alcohol: -anol
* Carboxylic Acid: -anoic acid
* Ester: -yl…anoate

Question 5

How does the number of carbons affect the volatility of organic compounds? (state)

Answer 5

• 1-4 carbons: Gas
• 5-15 carbons: Liquid
• > 15 carbons: Solid

Question 6

What are hydrocarbons?

Answer 6

Compounds made up of only hydrogen and carbon.

Question 7

What are isomers?

Answer 7

Compounds with the same molecular formula but different displayed structures.

Question 8

What is the general formula for alkanes?

Answer 8

CnH2n+2

Question 9

What is an example of an alkane?

Answer 9

Pentane (C5H12)

Question 10

How to get isomers of alkanes?

Answer 10

قص و الظق في النوص

Question 11

What are the three reactions of alkanes?

Answer 11

Substitution: in the presence of halogens and UV light
* Example: CH4 + Br2 → CH3Br + HBr

Combustion: complete and incomplete
* Complete: Produces CO2 + H2O
* Incomplete: Produces CO + H2O (or soot if oxygen is very low)

Cracking: Breaking down large hydrocarbons into smaller, more useful alkanes and alkenes

Question 12

What is the general formula for alkenes?

Answer 12

CnH2n

Question 13

What makes alkenes unsaturated?

Answer 13

The presence of a C=C double bond.

Question 14

How can you identify isomers of alkenes?

Answer 14

By moving the position of the double bond.

Example:
* But(1)ene → C=C-C-C
* But(2)ene → C-C=C-C

Question 15

Why are double bonds reactive?

Answer 15

The unstable repulsion force between the two bonds makes them highly reactive.

Question 16

What reactions do alkenes undergo?

Answer 16

Combustion (same as alkanes)

Addition reactions (breaking the double bond to add atoms):
* Hydrogenation: (+H2) → Forms an alkane (Requires Ni catalyst)
* Hydration: (+H2O) → Forms an alcohol (Requires H3PO4, 300°C, 65 atm, steam)
* Bromination: (+Br2) → Forms dibromo compounds (Orange bromine water turns colorless)

Question 17

What is crude oil?

Answer 17

A mixture of different alkanes.

Question 18

How is crude oil refined?

Answer 18

By fractional distillation, separating hydrocarbons based on boiling points.

Question 19

What are the fractions of crude oil (from most to least volatile)?

Answer 19

• Refinery Gas
• Gasoline (Petrol)
• Kerosene (Paraffin)
• Diesel
• Fuel Oil
• Bitumen

Question 20

What happens as you go down the fraction list?

Answer 20

• Higher boiling point
• More viscous
• Darker color
• Less flammable
• Less volatile
• Lower market demand and price

Question 21

What is cracking, and why is it important?

Answer 21

• Definition: The breakdown of large hydrocarbons into smaller, more useful alkanes and alkenes.
• Conditions: 600-700°C with a silica/alumina catalyst.

Question 22

How are alkenes made?

Answer 22

1. Cracking of crude oil
2. Dehydration of alcohols (Using H3PO4, 300°C, 65 atm)