CSS - PMS - CCE - PCS - General Science
Atomic Structure - Atomic Number
What does the atomic number of an element represent?
A. Number of electron shells
B. Number of neutrons only
C. Number of protons in the nucleus
D. Total protons plus neutrons
Correct Answer: C
Atomic number Z is defined as the number of protons in the nucleus.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
Which statement about soap is correct?
A. Soap molecules have both water-attracting and oil-attracting regions
B. Soap dissolves grease without interacting with water
C. Soap has no ionic or polar component
D. Soap is purely metallic
Correct Answer: A
The amphiphilic structure of soap allows it to bridge water and oily dirt.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
What is the main environmental concern associated historically with phosphate-rich detergents entering lakes?
A. Eutrophication
B. Loss of all dissolved salts
C. Ozone creation in lakes
D. Formation of diamonds
Correct Answer: A
Excess phosphate can stimulate algal growth, contributing to eutrophication and oxygen depletion.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
Which component is often added to detergents to improve cleaning by binding hardness ions?
A. Noble gases
B. Radioisotopes
C. Pig iron
D. Builders
Correct Answer: D
Builders such as phosphates or alternatives can soften water and improve surfactant performance.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
What is a surfactant?
A. A substance that lowers surface tension and helps water interact with oils or surfaces
B. A metal used only in batteries
C. A substance that always increases freezing point
D. A gas that destroys water
Correct Answer: A
Surfactants reduce interfacial tension and aid wetting, emulsification and cleaning.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
Why are many synthetic detergents more effective than soap in hard water?
A. They convert hard water into steam
B. They contain no carbon
C. They always make water acidic
D. They generally do not form the same insoluble precipitates with calcium and magnesium ions
Correct Answer: D
Many detergent surfactants remain soluble in the presence of hardness ions.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
Why does soap work poorly in hard water?
A. Soap evaporates instantly
B. Hard water has no molecules
C. Hard water contains no hydrogen
D. Calcium and magnesium ions form insoluble scum with soap
Correct Answer: D
Divalent calcium and magnesium ions react with soap anions to form insoluble salts.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
What structure forms when soap molecules surround grease droplets in water?
A. Crystals of sodium chloride
B. Micelles
C. Atomic nuclei
D. Gas bubbles only
Correct Answer: B
Micelles trap oily material in their hydrophobic interiors while hydrophilic heads face water.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
What part of a soap molecule interacts most strongly with grease and oil?
A. Water molecule
B. Hydrophobic hydrocarbon tail
C. Hydrophilic head only
D. Sodium ion only
Correct Answer: B
The nonpolar hydrocarbon tail dissolves or embeds in nonpolar grease and oil.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
What part of a soap molecule is attracted to water?
A. Carbon soot particle
B. Metallic core
C. Hydrophilic ionic head
D. Hydrophobic hydrocarbon tail
Correct Answer: C
Soap molecules are amphiphilic: their ionic or polar heads interact with water while hydrocarbon tails interact with grease.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Soap & Detergents
Soap is commonly produced by reacting fats or oils with a strong alkali in a process called what?
A. Saponification
B. Polymerization
C. Fermentation
D. Distillation
Correct Answer: A
Saponification converts triglycerides and a strong base into glycerol and salts of fatty acids called soaps.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
What does the term 'dose' mean in medicine?
A. The color of a medicine
B. The shelf on which medicine is stored
C. The trade name of a medicine
D. The measured amount of a medicine taken or administered at one time or on a schedule
Correct Answer: D
Dose refers to the quantity of a drug administered, often specified with frequency and duration.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
Which route of drug administration usually delivers a medicine directly into the bloodstream?
A. Inhalation only
B. Topical application
C. Oral tablet
D. Intravenous injection
Correct Answer: D
Intravenous administration places the drug directly into a vein, producing rapid systemic availability.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
Why should a prescribed antibiotic course generally be taken according to medical instructions?
A. The medicine changes into a virus
B. All bacteria become harmless immediately
C. Improper use can reduce effectiveness and contribute to antimicrobial resistance
D. Antibiotics become vitamins if stopped early
Correct Answer: C
Incorrect antibiotic use can leave surviving bacteria and promote selection of resistant strains.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
Which term describes a drug that reduces inflammation?
A. Anti-inflammatory
B. Antacid
C. Expectorant only
D. Anticoagulant only
Correct Answer: A
Anti-inflammatory medicines reduce inflammatory processes, swelling or associated pain.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
What is the role of a vaccine?
A. To act as a universal antibiotic
B. To replace red blood cells
C. To train the immune system to recognize a specific pathogen or antigen
D. To neutralize stomach acid
Correct Answer: C
Vaccines stimulate adaptive immune memory so the body can respond more effectively to future exposure.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
Why are antibiotics generally ineffective against viral infections such as the common cold?
A. Viruses are too large for medicines
B. Viruses contain no genetic material
C. Viruses lack the bacterial structures and processes targeted by antibiotics
D. Antibiotics work only above 100°C
Correct Answer: C
Antibiotics target bacterial features such as cell-wall synthesis or bacterial ribosomes, which viruses do not possess.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
Antacids are used mainly to neutralize excess acid in which organ?
A. Stomach
B. Pancreas
C. Lungs
D. Kidneys
Correct Answer: A
Antacids neutralize gastric hydrochloric acid and help relieve acid-related discomfort.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
What is the main purpose of an antipyretic medicine?
A. To increase blood glucose
B. To destroy all viruses
C. To reduce fever
D. To neutralize stomach acid only
Correct Answer: C
Antipyretics lower elevated body temperature associated with fever.
CSS - PMS - CCE - PCS - General Science
Applied Chemistry - Medicines
Which medicine category is primarily used to relieve pain?
A. Antiseptics
B. Vaccines
C. Antacids
D. Analgesics
Correct Answer: D
Analgesics reduce or relieve pain; examples include paracetamol and certain NSAIDs.