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.

151.

Mass of an element in a compound can be calculated through

A. Ar of the atoms/Mr of the compound
B. Mr of the atoms/Ar of the compound
C. (Ar of the atoms/Mr of the compound) × mass of sample
D. (Mr of the compound/Ar of the atoms) × mass of sample
Answer» D. (Mr of the compound/Ar of the atoms) × mass of sample
152.

Combining Copper(II) (Cu+2) with Oxygen (O₂) results in

A. CuO
B. Cu₂O
C. CuO₂
D. Cu(OH)₂
Answer» B. Cu₂O
153.

Valency of all these ions is negative 1, except

A. OH
B. PO₄
C. NO₃
D. Br
Answer» C. NO₃
154.

In H₂SO₄, chemical composition of oxygen is

A. 0.1111
B. 0.5032
C. 0.6531
D. 0.3265
Answer» D. 0.3265
155.

In Calcium Hydroxide (Ca(OH)₂), valency of Ca is

A. −1
B. −2
C. +1
D. +2
Answer» E.
156.

Metal that burns even more brightly than Magnesium (Mg) is

A. zinc
B. mercury
C. zirconium
D. diamond
Answer» D. diamond
157.

In writing chemical equations, inclusion of state symbols shall be done while

A. correct chemical formulae of reactants and products are written
B. the equation is being balanced to fulfill the law of conservation of mass
C. the equation has been balanced
D. the chemical formulae of products and reactants have been changed to bring about quick balancing
Answer» D. the chemical formulae of products and reactants have been changed to bring about quick balancing
158.

Sulfite ion can be written symbolically as

A. SO₄−2
B. SO₃−2
C. SO₄−3
D. S−2
Answer» C. SO₄−3
159.

Natural gas consists of

A. methane
B. ethane
C. propane
D. butane
Answer» B. ethane
160.

Hydrogen Sulfate (H₂SO₄) has

A. positive charge
B. negative charge
C. double negative charge
D. double positive charge
Answer» C. double negative charge
161.

If an acid reacts with an oxide, product will include H₂O and

A. a salt(s)
B. an acid (l)
C. a base
D. a gas
Answer» B. an acid (l)
162.

The ratio of hydrogen to oxygen in a water molecule is equal to

A. 1:2 ratio
B. 2:1 ratio
C. 4:3 ratio
D. 1:4 ratio
Answer» C. 4:3 ratio
163.

The simple molecular structure is of

A. Na₂O
B. MgO
C. SiO₂
D. P₄O₁₀
Answer» E.
164.

The compounds which are made up of benzene are known as

A. aryl compounds only
B. aromatic compounds only
C. benzyl compounds
D. aryl and aromatic compounds
Answer» E.
165.

Formula K₂SO₄ indicates that

A. 2 ions of Kalium are combined with 4 molecules of oxygen
B. 2 ions of Kalium are combined with 1 sulfate ion
C. 2 ions of potassium are combined with one sulfur and 4 oxygen molecules
D. 1 ion of potassium is combined with 1 sulfate ion
Answer» C. 2 ions of potassium are combined with one sulfur and 4 oxygen molecules
166.

In Na₂CO₃.10H₂O, highest percentage composition is of

A. sodium
B. oxygen
C. water
D. carbon
Answer» D. carbon
167.

In acid and base reaction, product includes

A. a salt(s)
B. water
C. acids
D. both a and b
Answer» D. both a and b
168.

Chemical formula of Copper(I) Oxide

A. Cu₂O
B. CuO₃
C. Cu(OH)₂
D. CuO
Answer» B. CuO₃
169.

The purification of compounds is usually done by chemists for formula analysis by the process of

A. gas chromatography
B. spectrometry
C. liquid chromatography
D. manometer
Answer» B. spectrometry
170.

Molar mass of calcium chloride is

A. 100.01gmol-1
B. 99.98gmol-1
C. 110.98gmol-1
D. 88.2gmol-1
Answer» D. 88.2gmol-1
171.

Sulfuric acid is synthesized by the process of

A. Haber
B. contact
C. electrolysis
D. hydrolysis
Answer» C. electrolysis
172.

Formula of Calcium Hydrogen Carbonate indicates

A. that the charge on Ca is +2
B. the charge on HCO₃ is −1
C. that for each molecule of calcium hydrogen carbonate, one ion of Ca and two ions of hydrogen carbona
D. all of these
Answer» E.
173.

In Na₂CO₃.10H₂O, percentage of Carbon is

A. 0.4201
B. 0.0422
C. 0.042
D. 0.46
Answer» D. 0.46
174.

In KHCO₃, highest percentage composition is of

A. Oxygen
B. Potassium
C. Carbon
D. Hydrogen
Answer» B. Potassium
175.

Ca(OH)₂ indicates that molecule is formed through

A. two Ca ions and one OH ion
B. One Ca ion and two OH ions
C. the charge on OH ion is -2
D. the charge on OH ion is +2
Answer» C. the charge on OH ion is -2
176.

Empirical formula can be obtained if following is known:

A. %age or mass of each element
B. relative atomic mass Ar
C. structural formula
D. both a and b
Answer» E.
177.

Covalent compounds

A. are not made of ions
B. are not formed through exchange of electrons
C. formulae cannot be worked out
D. all of these
Answer» E.
178.

Magnesium (Mg) burns in oxygen (O₂) to form

A. magnesium peroxide (Mg₂O₂)
B. magnesium hydroxide (Mg(OH)₂)
C. magnesium oxide (MgO)
D. magnesium dioxide (MgO₂)
Answer» D. magnesium dioxide (MgO₂)
179.

In a benzene molecule, each carbon atom shares one pair of electrons to

A. neighboring atom on one side
B. neighboring atom on other side
C. hydrogen atom
D. all of above
Answer» E.
180.

In Sulfuric Acid (H₂SO₄), chemical composition of sulfur is

A. 0.0204
B. 0.3265
C. 0.6531
D. 0.9821
Answer» C. 0.6531
181.

Organic molecules with similar relative molecular mass have alcohols (CₙH₂ₙ₊₁OH) bearing high

A. boiling point
B. polarity
C. volatility
D. Sublimation point
Answer» B. polarity
182.

When Carbon ions (C±4) react with Carbon Dioxide gas (CO₂), product will be

A. methane
B. ethane
C. propane
D. carbon monoxide
Answer» E.
183.

Consider CaCO₃ and HCl as reactants, how many molecules of CaCl₂ will be formed in products

A. 1
B. 2
C. 3
D. 4
Answer» B. 2
184.

Valency of nitrogen can be

A. 2 or 4
B. 4 or 6
C. 3 or 5
D. 2 or 3
Answer» D. 2 or 3
185.

Calcium carbonate CaCO₃ is a

A. solid
B. liquid
C. gas
D. aqueous
Answer» B. liquid
186.

π-bonds in benzene spread over all six carbons, hence they are called

A. delocalized
B. spectators
C. inhibitors
D. invaders
Answer» B. spectators
187.

Molar mass of potassium hydrogen carbonate KHCO₃ is

A. 90.15g/mol
B. 100.115g/mol
C. 111.127g/mol
D. 119.21g/mol
Answer» C. 111.127g/mol
188.

In Na₂CO₃, relative atomic mass of Carbon is

A. 12
B. 24
C. 36
D. 48
Answer» B. 24
189.

Greatest proportion by mass of nitrogen is in

A. Hydrazine (N₂H₄),
B. ammonium nitrate (NH₄NO₃)
C. ammonium sulphate (NH₄)₂SO₄
D. urea (NH₂CONH₂)
Answer» B. ammonium nitrate (NH₄NO₃)
190.

Chemical formula of monohydrate monosodium phosphate is

A. H₂ONaPO₂
B. PO₂NaH₂O
C. NaH₂PO₄.H₂O
D. NaH₃PO₂.H₂O
Answer» D. NaH₃PO₂.H₂O
191.

Chemical formula of aluminum oxide is

A. Al₂O₃
B. AlO₄
C. Al₂O₅.H₂O
D. Al₂O₅
Answer» B. AlO₄
192.

Symbol of Gold has been derived from its Latin name

A. Argentum
B. Argon
C. Aurum
D. Augmenten
Answer» D. Augmenten
193.

Valency is numerically equal to

A. the charge of an ion
B. the combining power of an atom
C. the combining power of a radical
D. all of these
Answer» E.
194.

Chemical formula of calcium nitrate is

A. CNOH
B. Ca(NO₃)₂
C. CaNO₃
D. CaNO₃
Answer» C. CaNO₃
195.

In Na₂CO₃, relative atomic mass of Oxygen is

A. 12
B. 24
C. 36
D. 48
Answer» E.
196.

If atomic mass of copper is 63.546, mass percent of copper in Cu₂O will be

A. 0.7898
B. 0.8098
C. 0.8882
D. 0.8678
Answer» D. 0.8678
197.

In Na₂CO₃.10H₂O, percentage of water is

A. 0.5009
B. 0.1699
C. 0.6507
D. 0.6294
Answer» E.
198.

A white smoke consisting of fine white solid particles is formed by

A. propane
B. butane
C. magnesium oxide
D. tin oxide
Answer» D. tin oxide
199.

All of these radicals have a valency of 1, except

A. OH
B. CO₃
C. NO₃
D. HCO₃
Answer» C. NO₃
200.

Formula of carbonic acid is

A. HCO₂
B. HCHO₃
C. H₂CO₂
D. H₂CO₃
Answer» E.