Explore topic-wise MCQs in Science.

This section includes 255 Mcqs, each offering curated multiple-choice questions to sharpen your Science knowledge and support exam preparation. Choose a topic below to get started.

51.

Major portion of mixture of hydrocarbons like crude oil is composed of

A. ester
B. alcohol
C. alkanes
D. propane
Answer» D. propane
52.

The molecular formula helps in

A. writing balanced equation only
B. calculating molar mass only
C. calculating moles
D. writing balanced equation and calculating molar mass
Answer» E.
53.

The reaction in which replacement of one atom or group of atoms are involved is termed as

A. addition reaction
B. elimination reaction
C. substitution reaction
D. oxidation
Answer» D. oxidation
54.

In the condensation of polymerization, monomers are involved which contain functional groups of

A. same kind
B. different kind
C. all groups
D. none of above
Answer» C. all groups
55.

Breakdown of any molecule with water (H₂O) in any reaction is

A. addition reaction
B. elimination reaction
C. substitution reaction
D. hydrolysis
Answer» E.
56.

Plastics we use in our everyday life is made up of

A. wood
B. rubber
C. polymers
D. none of above
Answer» D. none of above
57.

Monomers of ethene in thousand numbers react together in addition- polymerization to produce

A. polyethene
B. polyamides
C. polyesters
D. polyethane
Answer» B. polyamides
58.

Friedrich August Kekule's structure of 'benzene' was the inspiration of a

A. chemist
B. nature
C. dream
D. cloud
Answer» D. cloud
59.

Chlorobenzene is one of

A. halogens
B. amines
C. Halogenoarenes
D. hydrocarbons
Answer» D. hydrocarbons
60.

Organic compounds which contain one more than one benzene rings are termed as

A. arenes
B. aryls
C. acyls
D. benzenes
Answer» B. aryls
61.

The formula of benzene is

A. C₆H₆
B. C₂H₆
C. C₆H₁₂
D. CH
Answer» B. C₂H₆
62.

Vanillin is found in seed pods of

A. vanilla orchid
B. rose
C. vanilla tree
D. vanilla roots
Answer» B. rose
63.

The number of sigma bonds in benzene is

A. 2
B. 3
C. 4
D. 1
Answer» C. 4
64.

Hydrochloric Acid (HCl) and Silver Nitrate (AgNO₃) react to form

A. AgCl + HNO₃
B. HNO₃ + Ag(Aq)
C. Ag (s) + H₂O + N₂
D. Hydrogen gas is bubbled off
Answer» B. HNO₃ + Ag(Aq)
65.

Relative molecular mass of Sulfuric Acid (H₂SO₄) is

A. 98
B. 58
C. 108
D. 120
Answer» B. 58
66.

Phosphorus can have a valency of

A. 2 or 4
B. 4 or 6
C. 3 or 5
D. 2 or 1
Answer» D. 2 or 1
67.

To balance Al(OH)₃ + HNO₃ → Al(NO₃)₃ + H₂O, number of H₂O molecules produced will be

A. 2
B. 4
C. 6
D. 8
Answer» D. 8
68.

Two Greek words 'element' and 'measure' constitutes the word

A. spectrometry
B. stoichiometry
C. elemetry
D. geometry
Answer» C. elemetry
69.

The general formula for alcohols is

A. CₙH₂ₙ
B. CₙH₂ₙ₊₁
C. CₙH
D. CH₃
Answer» C. CₙH
70.

Formula of Nitrogen Trichloride (NCl₃) is

A. NaCl₂
B. NaCl₃
C. NCl₃
D. N₂Cl₃
Answer» D. N₂Cl₃
71.

Formula of calcium hydrogen sulphate is

A. CaHSO₄
B. Ca(HCO₃)₃
C. Ca(HSO₄)₃
D. Ca(HSO₄)₂
Answer» E.
72.

Charge on Sulphur can be

A. 2 or 4
B. 4 or 6
C. 3 or 5
D. 2 or 3
Answer» C. 3 or 5
73.

Hydrocarbons are the main source of

A. petrol
B. diesel
C. kerosene
D. all of above
Answer» E.
74.

State symbols include

A. s
B. l and aq
C. g
D. all of these
Answer» E.
75.

Symbol Hg stands for

A. helium
B. Hydragyrum
C. hydrogen
D. Natrium
Answer» C. hydrogen
76.

Valency of Plumbum can be

A. 2 or 4
B. 4 or 6
C. 3 or 5
D. 2 or 3
Answer» B. 4 or 6
77.

In magnesium oxide, magnesium ion requires only one oxygen ion because

A. the valency of oxygen is −1
B. the valency of Oxygen is −2
C. the valency of magnesium is +1
D. the formula of magnesium oxide is 2MgO
Answer» C. the valency of magnesium is +1
78.

The organic molecules containing hydroxyl group are called

A. esters
B. alcohols
C. aldehydes
D. ethane
Answer» C. aldehydes
79.

State symbol indicate the

A. state form
B. the solubility
C. the rigidity
D. the volatility
Answer» B. the solubility
80.

Chemical formula of Potassium Hydrogen Carbonate

A. KHCO₃
B. K₂CO₃.H₂O
C. KCO₃
D. K₂CO₄.H₂O
Answer» B. K₂CO₃.H₂O
81.

Formula of carbonic acid indicates that

A. for each ion of Carbon, two ions of hydrogen are required
B. for each ion of H, two carbonate ions are required
C. for each carbonate ion, two ions of hydrogen are required
D. for two carbonate ions, three ions of Hydrogen are required
Answer» D. for two carbonate ions, three ions of Hydrogen are required
82.

The number of electrons (e⁻) which are needed to complete the outer shell of each atom determines formula of

A. covalent compound
B. ionic compound
C. co-ordinate compound
D. metallic compound
Answer» B. ionic compound
83.

SO₄⁻² is the formula of

A. sulphur
B. sulphate
C. sulphuric acid
D. sulphide
Answer» C. sulphuric acid
84.

Law of conservation of mass

A. ensures that number of atoms of elements before and after the reaction are same
B. is important for strong Van der Waals' forces
C. is important to increase the volatility of metals
D. is important for melting and boiling points of metals only
Answer» B. is important for strong Van der Waals' forces
85.

Formula of Copper Hydroxide is

A. Cu(OH)₂
B. CuHOH
C. CuO₂
D. CuH₂O
Answer» B. CuHOH
86.

If Magnesium Carbonate (MgCO₃) reacts with Hydrochloric Acid (HCl), products will involve

A. magnesium chloride
B. carbonic acid
C. hydrogen gas
D. carbon dioxide
Answer» D. carbon dioxide
87.

In Na₂CO₃.10H₂O, relative formula mass is

A. 158
B. 186
C. 286
D. 288
Answer» D. 288
88.

Chemical composition of a compound

A. is fixed
B. can be obtained through relative molecular mass
C. is variable
D. both a and b
Answer» E.
89.

Chemical formula of Magnesium Carbonate is

A. MgCO₃. H₂O
B. MgCO₃
C. Mg₂CO₃
D. Mg₃CO₃
Answer» C. Mg₂CO₃
90.

Hydrogen Chloride (HCl) is a

A. ionic compound
B. covalent compound
C. metallic compound
D. both a and b
Answer» E.
91.

The molecules of alcohol have

A. hydrogen bonding
B. dipole forces
C. Van der Waals's forces
D. covalent bonding
Answer» B. dipole forces
92.

In Na₂CO₃.10H₂O, percentage of sodium is

A. 0.1678
B. 0.1608
C. 0.1659
D. 0.1684
Answer» C. 0.1659
93.

In 10H₂O, total units of water molecules are

A. 130
B. 150
C. 180
D. 220
Answer» D. 220
94.

Chemical formula of Sodium Sulfite is

A. Na₂SO₃
B. Na(SO₄)₂
C. Na₂CO₃.10H₂O
D. NaH₂PO₄.H₂O
Answer» B. Na(SO₄)₂
95.

Valency of magnesium is

A. +1
B. +2
C. -1
D. -2
Answer» C. -1
96.

Relative atomic mass of 3O₃ is

A. 48
B. 140
C. 180
D. 320
Answer» D. 320
97.

MgCO₃ + HCl reacts to form carbonic acid, which decomposes into

A. water
B. CO₂
C. gases
D. both a and b
Answer» D. both a and b
98.

When hydroxyl group is attached to carbon atom bonded to two other carbon atoms, the alcohol formed is

A. primary alcohol
B. secondary alcohol
C. tertiary alcohol
D. quaternary alcohol
Answer» C. tertiary alcohol
99.

Molar mass of Copper Oxide (Cu₂O) is

A. 113.14g/mol
B. 139.33g/mol
C. 173.298g/mol
D. 143.09g/mol
Answer» E.
100.

Copper can have a charge of

A. 2 or 4
B. 4 or 6
C. 3 or 5
D. 2 or 1
Answer» E.