Topic 4A - Part 1

Question 1

Define a hazard

Answer 1

A hazard is anything that could cause harm

Question 2

Define a risk

Answer 2

A risk is the likelihood of a hazard causing harm.

Question 3

In the context of chemistry, what are hazards?

Answer 3

Hazards could be things like inhalation of, spillage of, or contact with harmful chemicals, or breaking glassware.

Question 4

List the top five hazardous properties associated with organic compounds

Answer 4

• Flammability
• Volatility
• Toxicity
• Corrosivity

Question 5

What does flammable mean?

Answer 5

Easily ignites

Question 6

Define volatile

Answer 6

Has a low boiling point so readily evaporates at temperatures used in common lab experiments

Question 7

Define Toxic

Answer 7

can cause damage to an organism

Question 8

Define Corrosive

Answer 8

can cause damage to living tissue

Question 9

What is risk assessment?

Answer 9

Involves identifying the possible hazards in an experiment and planning how to reduce or eliminate the risk of that hazard.

Question 10

What does organic chemistry concern mostly?

Answer 10

Organic chemistry mainly concerns the properties and reactions of hydrocarbons, compounds that contain only carbon and hydrogen atoms.

Question 11

What do hydrocarbons form?

Answer 11

Hydrocarbons form a series of compounds with similar structures and formulae that can be represented in many different ways.

H H
| |
H–C–C–H
|
H

Question 12

Define nomenclature

Answer 12

The set of rules that outline how different organic compounds should be named and how their formulae are represented.

Question 13

What are the top 6 different ways of writing and representing organic compounds?

Answer 13

• Empirical Formula
• Molecular Formula
• General Formula
• Structural Formula
• Displayed Formula
• Skeletal Formula

Question 14

What is the empirical formula?

Answer 14

The simplest whole number ratio of the atoms present in a compound.

Question 15

What is the skeletal formula?

Answer 15

-shows only the bonds in a compound and any non-carbon atoms.
Vertices are carbon atoms.

Question 16

What is the molecular Formula?

Answer 16

the actual number of atoms of each element present in a molecule ( covalent compound) or formula unit ( ionic compound) of a compound.

Question 17

What is the displayed formula?

Answer 17

-shows every atom and every bond in an organic compound.

Question 18

What is the general formula?

Answer 18

all members of a homologous organic series follow the general formula.

Question 19

What is the structural formula?

Answer 19

shows the structural arrangement of atoms within a molecule.

Question 20

Define heterologous series

Answer 20

A heterologous series refers to a group of compounds that have different functional groups but still show some similarity in structure or chemical behavior. Unlike a homologous series, the compounds in a heterologous series do not follow a consistent pattern of increasing by CH₂ groups

For example:

Alcohols (R-OH)
Ethers (R-O-R’)
Aldehydes (R-CHO)
These compounds belong to different functional groups but may share some structural or chemical properties.

Question 21

What is a homologous series?

Answer 21

A homologous series is a group of organic compounds that have:

The same functional group (like alcohol, alkene, or alkane).
A similar general formula (e.g., CnH2n+2 for alkanes).
A pattern where each successive compound differs by a CH2 group.
For example, the alkane series:

Methane (CH4)
Ethane (C2H6)
Propane (C3H8)
These compounds show gradual changes in physical properties (like boiling points) but react chemically in similar ways due to the same functional group.

Question 22

Define the term functional group

Answer 22

A functional group is a specific group of atoms within a molecule that determines the chemical properties and reactions of that molecule. It is the reactive part of an organic compound.

Examples of Functional Groups:
Hydroxyl group (-OH): Found in alcohols.
Carboxyl group (-COOH): Found in carboxylic acids.
Carbonyl group (C=O): Found in aldehydes and ketones.
Amino group (-NH2): Found in amines.
Halogens (e.g., -Cl, -Br): Found in haloalkanes.

The functional group defines how a molecule interacts chemically, regardless of the size of the molecule it is part of.

Question 23

Fill in the Gap

Compounds are named according to rules laid out by the … … .. .. .. .. .. or (….)

Answer 23

International Union of Pure and Applied Chemistry (IUPAC)

Question 24

What are side chains?

Answer 24

Side chains are groups of atoms attached to the main chain (or backbone) of a molecule. In organic chemistry, the main chain is usually the longest continuous chain of carbon atoms, while the side chains are branches or smaller groups connected to it.

Key Points About Side Chains:
Structure: Side chains can be a single atom (like a halogen) or a group of atoms (like a methyl group, CH3).
Function: They can change the chemical and physical properties of the main molecule, such as solubility or reactivity.
Example: In 2-methylpropane, the main chain is propane, and the side chain is a methyl group (CH3) attached to the second carbon.
Side chains are often represented in structural formulas to describe how molecules are branched.

Question 25

List the general rules for naming compunds?

Answer 25

General Rules
1. Functional groups and side chains are given, if necessary, with the number corresponding to the carbon they are attached to.
2. Numbers are separated by commas
3. Numbers and words are separated by hyphens.
4. If more than one particular side chain of functional group is present then one of the following prefixes is added: di - (2), tri - (3), tetra (4), etc.
5. The carbon chain is numbered in ascending order from the end of the chain nearest a functional group.
6. If multiple prefixes are present, they are included in alphabetical order.

Example: The displayed structure of butan-2,3-diol.
This compound only has single carbon-carbon bonds, so is an alkane. Its longest chain of carbon atoms is 4, giving the stem butan-, and it has two alcohol functional groups on carbons 2 and 3.