chemistry in everyday life — BSSC Chemistry

50 Questions • 30 Minutes • Chemistry Mock Test in Hindi and English

Sample Questions from this Test

Question 1:

Consider the following statements regarding the composition and setting of Portland cement:
1. Calcium oxide (CaO) holds the highest percentage share, comprising 60-70% of the cement.
2. Gypsum is added to cement to accelerate the process of setting.
3. The setting of cement is an exothermic process, which is why cement structures are cooled with water for days.
Which of the above statements is/are correct?
A.1 and 2 only
B.1 and 3 only
C.2 and 3 only
D.All of the above

• Key Fact
Portland cement roughly contains 60-70% CaO, and the setting process releases heat (exothermic).

• Supporting Detail
Gypsum is added specifically to slow down (retard) the setting process so the cement hardens properly.

• Related Concept
Silica (20-25%) and Alumina (5-10%) are the next major components of cement.

• Why wrong options are wrong
Statement 2 is incorrect because gypsum increases (slows) the setting time; it does not accelerate it.

• Exam Trick
"Gypsum = Go Slow". It prevents flash setting of cement.

• Additional Info
Mortar is a mixture of cement, sand, and water used for plastering walls.

Question 2:

Match List-I (Types of Glass) with List-II (Specific Uses):
List-I:
A. Pyrex glass
B. Crookes glass
C. Photochromatic glass
D. Flint glass

List-II:
1. Cuts off ultraviolet (UV) rays (Spectacle lenses)
2. Pharmaceutical containers and lab apparatus
3. Making bulbs and optical instruments (high refractive index)
4. Darkens temporarily on exposure to bright light
A.A-2, B-1, C-4, D-3
B.A-2, B-4, C-1, D-3
C.A-3, B-1, C-4, D-2
D.A-1, B-2, C-3, D-4

• Key Fact
Pyrex is for lab use, Crookes cuts UV rays, Photochromatic darkens in light, and Flint is for optical instruments.

• Supporting Detail
Flint glass contains sodium, potassium, and lead silicates, which gives it a high refractive index.

• Related Concept
Photochromatic glass turns dark due to the presence of an embedded microcrystalline silver compound (silver chloride).

• Why wrong options are wrong
Any other combination incorrectly matches the specialized property of the glass with its use.

• Exam Trick
Crookes cuts "Crooked" UV rays. Photochromatic works like "Photos" (reacts to light).

• Additional Info
Safety glass has three layers joined by heat/pressure and is used in vehicle windshields.

Question 3:

Assertion (A): Bakelite and Melamine are examples of thermoplastic polymers.
Reason (R): Thermoplastics are plastics that get deformed easily on heating and can be bent easily.
A.Both A and R are true, and R is the correct explanation of A
B.Both A and R are true, but R is NOT the correct explanation of A
C.A is true but R is false
D.A is false but R is true

• Key Fact
Bakelite and Melamine are Thermosetting plastics, not thermoplastics.

• Supporting Detail
Thermosetting plastics are soft on heating but become solid and hard upon increasing the temperature, unable to be remelted.

• Related Concept
Examples of thermoplastics include polythene, polystyrene, and PVC.

• Why wrong options are wrong
Assertion A is factually incorrect as it misclassifies Bakelite and Melamine.

• Exam Trick
Thermoplastic = "Plastic" (can change shape). Thermosetting = "Set" (shape is permanently fixed).

• Additional Info
Melamine is heavily used in firemen's uniforms because it is flame-resistant.

Question 4:

Fill in the blank: In a foam fire extinguisher, an aqueous solution of Aluminium sulphate is kept in the inner part, and a solution of __________ is kept in the outer part to extinguish fires in oily substances and wax.
A.Sodium carbonate
B.Sodium bicarbonate
C.Carbon tetrachloride
D.Sodium chloride

• Key Fact
A foam fire extinguisher uses Aluminium solution in the inner part and sodium bicarbonate solution in the outer part.

• Supporting Detail
These chemicals react when the extinguisher is used to produce foam and carbon dioxide, cutting off the oxygen supply.

• Related Concept
In a soda-acid fire extinguisher, Sodium carbonate (Na₂CO₃) and hydrochloric acid (HCl) are used.

• Why wrong options are wrong
Carbon tetrachloride (C.T.C) is used in electrical fire extinguishers.

• Exam Trick
Foam Fire Extinguisher = Alum + Baking Soda (Sodium bicarbonate).

• Additional Info
Bromochlorodifluoromethane is also used alongside C.T.C for extinguishing electrical fires.

Question 5:

Which of the following is an electro-positive chemical coagulant widely used in the flocculation method of water treatment?
A.Polyaluminium chloride (PAC)
B.Nitrogen dioxide
C.Aluminium sulphate
D.Magnesium bisulphite

• Key Fact
Positively charged chemicals like Aluminium sulphate (alum) and ferric chloride are the most widely used flocculants.

• Supporting Detail
Flocculation is used to clump together fine particles in water so they can be easily filtered out.

• Related Concept
Disinfectants like chlorine are used after filtration to kill viruses, parasites, and bacteria.

• Why wrong options are wrong
Nitrogen dioxide is an air pollutant gas. Magnesium bisulphite is a food preservative.

• Exam Trick
"Alum" (Aluminium sulphate) is traditionally used in Indian households to clean muddy water.

• Additional Info
Aluminium sulphate formula is Al₂(SO₄)₃, and ferric chloride is FeCl₃.

Question 6:

Find the Odd One Out regarding explosives and their constituents:
A.Dynamite — Manufactured by absorbing nitroglycerine in saw dust.
B.Nobel Oil — Also known as Trinitroglycerin (TNG).
C.Amatol — An explosive that does NOT contain nitroglycerine as an essential constituent.
D.RDX — Discovered by Alfred Nobel and used in blasting tunnels.

• Key Fact
RDX was discovered by Georg Friedrich Henning in 1899, not Alfred Nobel.

• Supporting Detail
Alfred Nobel actually discovered Dynamite in 1863.

• Related Concept
RDX is also known as Cyclonite or Plastic Explosive (PBE).

• Why wrong options are wrong
Options A, B, and C are entirely correct factual statements.

• Exam Trick
Nobel = Dynamite (He created the Nobel Prize). RDX = Henning.

• Additional Info
Amatol is a mixture of TNT and ammonium nitrate, omitting nitroglycerine.

Question 7:

Read the following two statements regarding the classification of dyes and choose the correct option:
Statement I: Alizarin is a natural dye that is classified under Anthraquinone dyes based on its chemical composition.
Statement II: Indigo is an example of an Azo dye, which contains chromophore groups responsible for colour.
A.Both Statement I and Statement II are true.
B.Both Statement I and Statement II are false.
C.Statement I is true but Statement II is false.
D.Statement I is false but Statement II is true.

• Key Fact
Alizarin belongs to Anthraquinone dyes. Indigo is classified as an Indigo dye or Vat dye, not an Azo dye.

• Supporting Detail
Methyl orange and Congo red are actual examples of Azo dyes.

• Related Concept
Vat dyes are used to dye cotton clothes directly (e.g., Indigo).

• Why wrong options are wrong
Statement II incorrectly categorizes Indigo.

• Exam Trick
Azo = Methyl Orange & Congo Red. Anthraquinone = Alizarin (A to A).

• Additional Info
Nitro and azo groups act as "Chromophore groups" which are responsible for imparting colour.

Question 8:

A patient is suffering from severe mental stress and mild mental illness. Which category of drugs should a doctor prescribe to effectively treat this condition?
A.Analgesics
B.Tranquilizers
C.Anaesthetics
D.Antipyretics

• Key Fact
Tranquilizers are drugs specifically used in the treatment of mental stress, mild and acute mental illnesses.

• Supporting Detail
They work by calming the nervous system without necessarily inducing sleep like strong sedatives.

• Related Concept
Analgesics are used for pain relief (e.g., Aspirin, Ibuprofen).

• Why wrong options are wrong
Anaesthetics reduce overall sensation. Antipyretics reduce fever.

• Exam Trick
"Tranquil" means calm. Hence, Tranquilizers calm the mind.

• Additional Info
Antiseptics inhibit bacterial growth without harming human tissues.

Question 9:

Match List-I (Chemicals in Food) with List-II (Characteristics/Formulas):
List-I:
A. Aspartame
B. Sucralose
C. Sodium benzoate
D. Alitame

List-II:
1. Trichloro derivative of sucrose that does not break down in the bloodstream
2. Most common food preservative used to prevent spoiling
3. Dipeptide sweetener that is 2000 times sweeter than cane sugar
4. Methyl ester of phenylalanine dipeptide or aspartic acid
A.A-4, B-1, C-2, D-3
B.A-3, B-1, C-4, D-2
C.A-4, B-2, C-1, D-3
D.A-1, B-4, C-3, D-2

• Key Fact
Aspartame is a methyl ester; Sucralose is a trichloro derivative; Alitame is 2000x sweeter; Sodium benzoate is a preservative.

• Supporting Detail
Saccharin (o-Sulfobenzimide) is another artificial sweetener, about 500 times sweeter than sugar.

• Related Concept
Food preservatives like Sodium benzoate inhibit mold and yeast growth.

• Why wrong options are wrong
Any mismatched pair contradicts the specific chemical properties provided in the text.

• Exam Trick
Aspartame = Phenylalanine/Aspartic acid. Alitame = 2000x (Astronomical).

• Additional Info
Chemical formula of Sucralose is C₁₂H₁₉Cl₃O₈.

Question 10:

Assertion (A): Sawdust is commonly used to adulterate coriander powder.
Reason (R): Turmeric powder is frequently adulterated with lead(II) chromate or metanil yellow to enhance its natural yellow color.
A.Both A and R are true, and R is the correct explanation of A
B.Both A and R are true, but R is NOT the correct explanation of A
C.A is true but R is false
D.A is false but R is true

• Key Fact
Both statements are correct factual examples of food adulteration, but one does not logically cause or explain the other.

• Supporting Detail
Adulterants are secretly added to compromise food safety (e.g., chalk powder in sugar, papaya seeds in black pepper).

• Related Concept
Metanil yellow is tested using hydrochloric acid, which yields a pink/violet-red colour.

• Why wrong options are wrong
Option A is wrong because R is an independent fact about turmeric, not the reason why sawdust is added to coriander.

• Exam Trick
Sawdust matches the texture of coriander, and Metanil Yellow matches the colour of turmeric.

• Additional Info
Sudan dye is an azo dye used to adulterate hot paprika.

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