SSS 1: INTRODUCTION TO CHEMISTRY
CHEMISTRY is a branch of pure science that deals with the study of the nature, structure, composition, properties, and uses of matter. The scientist who studies chemistry is called a CHEMIST
BRANCHES OF CHEMISTRY
The four main branches of chemistry are
1. Physical chemistry
2. Organic chemistry
3. Inorganic chemistry
4. Analytical chemistry
Physical chemistry deals with the physical aspects of chemistry such as quantum theory, heat, electricity, etc.
Organic chemistry deals with the study of carbon and its compounds
Inorganic chemistry deals with the study of elements, their properties, and uses
Analytical chemistry: is a branch of chemistry that focuses on identifying, separating, and quantifying chemical substances. Analytical chemistry is divided into two which are:
(a) Qualitative analysis
(b) Quantitative analysis
Qualitative analysis: It is used to determine which substances or ions are present in a chemical substance
Quantitative analysis: It shows the amount or concentration of a particular substance present in a chemical substance.
REASONS FOR STUDYING CHEMISTRY
The reasons for studying chemistry are:
1. To acquire knowledge about the matter
2. To give training in the scientific method
3. To meet basic needs such as food, clothing, shelter, health, etc
4. To provide solutions to problems
5. To explore new things which are unknown to mankind.
SCIENTIFIC METHOD
The scientific method is also known as scientific discovery. It is defined as a way of studying problems objectively to establish facts through testing and experimentation.
The scientific methods include:
1. Observation
2. Hypothesis
3. Experiment
4. Theory
5. Scientific law or principle.
Observation: Observation involves the use of senses to perceive what is happening in the environment.
Hypothesis: Hypothesis means to put forward a reasonable explanation for an observation.
Experiment: The experiment is a scientific procedure undertaken to demonstrate a known fact.
Theory: Theory is a set of principles on which the practice of an identity is based. A theory is established when a hypothesis has been tested and found to be correct within the limited available evidence.
Scientific law: Scientific law is a statement that confirms the hypothesis after extensive tests. A theory that has been extensively tested and proven correct without any exception becomes a scientific law.
USES OF CHEMISTRY
Chemistry has contributed greatly toward providing our basic needs and improving the quality of life through:
1. Provision of food I.e through the use of fertilizer, herbicides, and insecticides in agriculture to boost crop production
2. Provision of clothing with the help of man-made textile fibers.
3. Provision of modern means of transportation
4. Provision of drugs and other medical usages
5. Provision of modern-day housing materials.
6. Provision of military ammunition
7. Provision of knowledge in space science
CAREER PROSPECT IN CHEMISTRY
There is a wide range of career opportunities for those who study chemistry at any level. Individuals can choose a career from different fields such as
1. Science education
2. Pharmaceuticals or drug development.
3. Mining and metallurgy
4. Chemical engineering
5. Petroleum and petrochemical engineering
6. Medicine and Surgery
7. Quality control
8. Medical analysis/ Forensic medicine.
9. Environmental Chemistry
10. Science laboratory technology
11. Biochemistry etc.
ADVERSE EFFECTS OF CHEMISTRY
The adverse effects of chemistry include
1.Rusting
2.Pollution
3.Drug abuse
Rusting is also known as corrosion of iron. It is defined as the interaction of Iron with air and water to produce rust
Features of rusting
- Rusting is an oxidation process
- Rusting of iron takes place in the presence of oxygen and moisture
- the rust formed is reddish-brown
- the major constituent of rust is hydrated iron (lll) oxide (Fe2O3)
- rusting is similar to burning
Prevention of rusting
Ways of preventing rusting include:
1. Alloying
2. Galvanization
3. Electroplating
4. Cathodic protection
Class activities
1. Which branch of chemistry primarily investigates the relationship between the structure of matter and its energy transformations?
(a) analytical chemistry
(b) physical chemistry
(c) organic chemistry
(d) inorganic chemistry
2. The transition of a well-supported hypothesis into a scientific law requires that it:
(a) be accepted by a majority of scientists
(b) explain all natural phenomena without testing
(c) withstand repeated experimental verification without exception within its scope
(d) remain unchanged for a century
3. Which statement best distinguishes a scientific theory from a scientific law.
(a) theories are opinions, while laws are facts
(b) theories explain phenomena, whereas laws describe consistent natural relationships
(c) laws are hypotheses that have not been tested
(d) theories cannot be modified
4. Which analytical technique is primarily concerned with determining the concentration of a chemical species?
(a) qualitative analysis
(b) quantitative analysis
(c) organic synthesis
(d) electrochemistry
5. The scientific method is most accurately described as:
(a) a sequence of assumptions accepted without evidence
(b) a systematic process for investigating phenomena through observation and experimentation
(c) a philosophical argument without experimentation
(d) a mathematical proof of scientific facts
6. Which of the following is not a characteristic feature of rusting?
(a) it is an oxidation process
(b) it occurs only in the absence of oxygen
(c) it forms a reddish-brown product
(d) it requires moisture
7. The principal chemical constituent of rust is:
(a) iron(II) oxide (FeO)
(b) iron(II,III) oxide (Fe₃O₄)
(c) hydrated iron(III) oxide (Fe₂O₃·xH₂O)
(d) iron carbide (Fe₃C)
8. Which corrosion prevention method involves coating iron with zinc?
(a) alloying
(b) galvanization
(c) electroplating
(d) cathodic protection
9. In scientific inquiry, an observation primarily serves to:
(a) establish universal laws immediately
(b) generate questions and hypotheses for investigation
(c) eliminate the need for experimentation
(d) replace theoretical reasoning
10. Which branch of chemistry focuses predominantly on compounds containing carbon?
(a) inorganic chemistry
(b) analytical chemistry
(c) organic chemistry
(d) nuclear chemistry
11. A hypothesis is scientifically valuable only if it is:
(a) universally accepted before testing
(b) testable and capable of being supported or refuted by evidence
(c) consistent with personal beliefs
(d) impossible to disprove
12. Which of the following careers relies most heavily on quantitative analytical techniques for regulatory compliance?
(a) quality control
(b) science education
(c) environmental conservation alone
(d) textile design
13. Cathodic protection prevents corrosion primarily by:
(a) increasing the oxidation rate of iron
(b) making iron act as the cathode in an electrochemical cell
(c) removing all oxygen from the environment
(d) coating iron with plastic only
14. Which of the following best illustrates the societal contribution of chemistry?
(a) elimination of all environmental pollution
(b) development of fertilizers that improve agricultural productivity
(c) prevention of all diseases permanently
(d) replacement of biological sciences
15. The progression in the scientific method from observation to scientific law is most appropriately represented as:
(a) observation → theory → hypothesis → experiment → law
(b) hypothesis → observation → law → experiment → theory
(c) observation → hypothesis → experiment → theory → scientific law
(d) experiment → law → observation → hypothesis → theory
16. Which branch of chemistry would most likely investigate the thermodynamic feasibility of a chemical reaction?
(a) physical chemistry
(b) organic chemistry
(c) analytical chemistry
(d) inorganic chemistry
17. Which statement best explains why rusting is often compared with burning?
(a) both are reduction reactions
(b) both involve oxidation processes
(c) both occur only at high temperatures
(d) both produce carbon dioxide
18. Which of the following is the primary objective of qualitative analysis?
(a) determining reaction rates
(b) identifying the chemical species present in a sample
(c) measuring the mass of a sample only
(d) calculating molecular orbital energies
19. Which factor is indispensable for the rusting of iron under normal atmospheric conditions?
(a) nitrogen gas only
(b) carbon dioxide only
(c) oxygen and moisture
(d) ultraviolet radiation
20. Which statement best reflects the philosophical significance of the scientific method?
(a) scientific knowledge is based on objective evidence and reproducible experimentation
(b) scientific conclusions are determined by authority
(c) scientific laws cannot be revised under any circumstances
(d) experiments are unnecessary once a hypothesis is proposed.
THEORY QUESTIONS
1. Introduction to Chemistry
(a) Define chemistry.
(b) Who is a chemist?
(c) State four branches of chemistry.
2. Branches of Chemistry
(a) Explain physical chemistry.
(b) Differentiate between organic chemistry and inorganic chemistry.
(c) State two importance of analytical chemistry.
3. Analytical Chemistry
(a) What is analytical chemistry?
(b) Differentiate between qualitative analysis and quantitative analysis.
(c) State two uses of qualitative analysis.
4. Scientific Method
(a) Define the scientific method.
(b) List the five stages of the scientific method.
(c) Explain the following terms: observation, hypothesis, and experiment.
5. Theory and Scientific Law
(a) What is a scientific theory?
(b) What is a scientific law?
(c) State the condition under which a theory becomes a scientific law.
6. Importance of Chemistry
(a) State five reasons for studying chemistry.
(b) Mention five uses of chemistry in everyday life.
(c) Explain how chemistry has improved agriculture and medicine.
7. Career Opportunities in Chemistry
(a) State five career opportunities available to a student of chemistry.
(b) Explain the role of chemistry in medicine.
(c) Explain the role of chemistry in the petroleum industry.
8. Rusting
(a) Define rusting.
(b) State four features of rusting.
(c) State the conditions necessary for rusting to occur.
9. Prevention of Rusting
(a) Explain the following methods of preventing rusting: galvanization, electroplating, and alloying.
(b) State four methods of preventing rusting.
(c) Explain the importance of preventing rusting.
10. Adverse Effects of Chemistry
(a) State three adverse effects of chemistry.
(b) Explain drug abuse and pollution.
(c) Suggest four ways of reducing the adverse effects of chemistry.
Answers
1. (b)
2. (c)
3. (b)
4. (b)
5. (b)
6. (b)
7. (c)
8. (b)
9. (b)
10. (c)
11. (b)
12. (a)
13. (b)
14. (b)
15. (c)
16. (a)
17. (b)
18. (b)
19. (c)
20. (a)
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