Explore topic-wise MCQs in Chemistry.

This section includes 140 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

The most efficient agent for the absorption of \[S{{O}_{3}}\] is [KCET 1998]

A. \[98%{{H}_{2}}S{{O}_{4}}\]
B. \[80%{{H}_{2}}S{{O}_{4}}\]
C. \[20%\]oleum
D. \[90%{{H}_{2}}S{{O}_{4}}\]
Answer» B. \[80%{{H}_{2}}S{{O}_{4}}\]
2.

Match List I with List II and select the correct answer using the codes given below the lists List I List IIList - IList - II(A)Peroxide(1)\[{{C}_{3}}{{O}_{2}}\](B)Superoxide(2)\[Pb{{O}_{2}}\](C)Dioxide(3)\[K{{O}_{2}}\](D)Suboxide(4)\[{{H}_{2}}{{O}_{2}}\]Codes: [NDA 1999]

A. A-4 B-3 C-2 D-1
B. A-3 B-2 C-1 D-4
C. A-4 B-2 C-3 D-1
D. A-4 B-1 C-2 D-3
Answer» B. A-3 B-2 C-1 D-4
3.

Concentrated hydrochloric acid when kept in open air sometimes produces a cloud of white fumes. The explanation for it is that [AIEEE 2003]

A. Concentrated hydrochloric acid emits strongly smelling \[HCl\] gas all the time
B. Oxygen in air reacts with the emitted \[HCl\] gas to form a cloud of chlorine gas
C. Strong affinity of \[HCl\] gas for moisture in air results in forming of droplets of liquid solution which appears like a cloudy smoke
D. Due to strong affinity for water, concentrated hydrochloric acid pulls moisture of air towards itself. This moisture forms droplets of water and hence the cloud
Answer» C. Strong affinity of \[HCl\] gas for moisture in air results in forming of droplets of liquid solution which appears like a cloudy smoke
4.

Which of the following gas mixture is used by the divers inside the sea [AFMC 2004]

A. \[{{O}_{2}}+He\]
B. \[{{O}_{2}}+Xe\]
C. \[{{O}_{2}}+Ar\]
D. \[{{O}_{2}}+{{N}_{2}}\]
Answer» B. \[{{O}_{2}}+Xe\]
5.

The colour of liquid \[{{O}_{2}}\] is [BVP 2004]

A. Red
B. Dark blue
C. Pale yellow
D. Pale blue
Answer» E.
6.

Thermite is a mixture of [Pb. CET 2004]

A. \[C{{r}_{2}}{{O}_{3}}+A{{l}_{2}}{{O}_{3}}\]
B. \[F{{e}_{2}}{{O}_{3}}+Al\]
C. \[F{{e}_{2}}{{O}_{3}}+A{{l}_{2}}{{O}_{3}}\]
D. \[A{{l}_{2}}{{O}_{3}}+2Cr\]
Answer» C. \[F{{e}_{2}}{{O}_{3}}+A{{l}_{2}}{{O}_{3}}\]
7.

The noble gas was first time discovered by

A. Cavandish
B. William Ramsay
C. Rayleigh
D. Frankland
Answer» C. Rayleigh
8.

Nessler's reagent is [CPMT 2002]

A. Potassium in mercuric iodide
B. \[TiC{{l}_{4}}\]
C. Anhydrous \[AlC{{l}_{3}}\]
D. \[A{{l}_{2}}{{O}_{3}}/C{{r}_{2}}{{O}_{3}}\]
Answer» B. \[TiC{{l}_{4}}\]
9.

Four reactions are given below (i)\[2Li+2{{H}_{2}}O\to 2LiOH+{{H}_{2}}\] (ii)\[2Na+2{{H}_{2}}O\to 2NaOH+{{H}_{2}}\] (iii)\[2LiN{{O}_{3}}\xrightarrow{Heat}2LiN{{O}_{2}}+{{O}_{2}}\] (iv)\[2NaN{{O}_{3}}\xrightarrow{Heat}2NaN{{O}_{2}}+{{O}_{2}}\] Which of the above, if any, is wrong

A. (iv)
B. (iii)
C. (i)
D. None of these
Answer» C. (i)
10.

Increasing order of solubility is [AFMC 1987]

A. \[CaC{{O}_{3}},KHC{{O}_{3}},NaHC{{O}_{3}}\]
B. \[NaHC{{O}_{3}},KHC{{O}_{3}},CaC{{O}_{3}}\]
C. \[KHC{{O}_{3}},NaHC{{O}_{3}},CaC{{O}_{3}}\]
D. \[CaC{{O}_{3}},NaHC{{O}_{3}},KHC{{O}_{3}}\]
Answer» E.
11.

When \[S{{O}_{2}}\] is passed through acidified solution of \[{{H}_{2}}S\] [CPMT 1973, 81, 93]

A. \[{{H}_{2}}S{{O}_{4}}\] is formed
B. \[{{H}_{2}}S{{O}_{3}}\] is formed
C. Sulphur is precipitated
D. None of these
Answer» D. None of these
12.

The mixture of conc. HCl and potassium chlorate on heating gives [Roorkee 2000]

A. \[C{{l}_{2}}\] only
B. \[Cl{{O}_{2}}\]only
C. \[C{{l}_{2}}+Cl{{O}_{2}}\]
D. \[C{{l}_{2}}+Cl{{O}_{2}}+Cl{{O}_{3}}\]
Answer» D. \[C{{l}_{2}}+Cl{{O}_{2}}+Cl{{O}_{3}}\]
13.

Lithium aluminium hydride acts as [CPMT 1994]

A. Oxidising agent
B. Reducing agent
C. Both the above
D. None of these
Answer» C. Both the above
14.

Which one of the following is the true covalent oxide of iodine [MP PET/PMT 1988]

A. \[{{I}_{2}}{{O}_{4}}\]
B. \[{{I}_{2}}{{O}_{5}}\]
C. \[{{I}_{2}}{{O}_{7}}\]
D. \[{{I}_{2}}{{O}_{9}}\]
Answer» C. \[{{I}_{2}}{{O}_{7}}\]
15.

\[BaS{{O}_{4}}\] and carbon on heating reacts to produce [Pb. PMT 2004]

A. \[Ba+S{{O}_{2}}+C{{O}_{2}}\]
B. \[BaS+CO\]
C. \[BaS+{{O}_{2}}+S{{O}_{2}}\]
D. \[BaC{{O}_{3}}+S+{{O}_{2}}\]
Answer» C. \[BaS+{{O}_{2}}+S{{O}_{2}}\]
16.

Lead is maximum in [BVP 2004]

A. Soda glass
B. Jena glass
C. Pyrex glass
D. Flint glass
Answer» E.
17.

The first ionisation energies of alkaline earth metals are higher than those of the alkali metals. This is because [UPSEAT 2001]

A. There is increases in the nuclear charge of the alkaline earth metals
B. There is decreases in the nuclear charge of the alkaline earth metals
C. There is no change in the nuclear charge
D. None of these
Answer» B. There is decreases in the nuclear charge of the alkaline earth metals
18.

Red phosphorus is less reactive than yellow phosphorus because [DPMT 1982; JIPMER 1999;CBSE PMT 1999; RPET 2003]

A. Its colour is red
B. It is highly polymerized
C. It is hard
D. It is insoluble in \[{{C}_{2}}{{H}_{5}}OH\]
Answer» C. It is hard
19.

Nitrogen is liberated by the thermal decomposition of only [IIT 1991]

A. \[N{{H}_{4}}N{{O}_{2}}\]
B. \[Na{{N}_{3}}\]
C. \[{{(N{{H}_{4}})}_{2}}C{{r}_{2}}{{O}_{7}}\]
D. All the three
Answer» E.
20.

Which would quickly absorbs oxygen [CBSE PMT 1992; MP PET 1995]

A. Alkaline solution of pyrogallol
B. Conc. \[{{H}_{2}}S{{O}_{4}}\]
C. Lime water
D. Alkaline solution of \[CuS{{O}_{4}}\]
Answer» B. Conc. \[{{H}_{2}}S{{O}_{4}}\]
21.

Which of the following is the life saving mixture for an asthma patient [MP PMT 2001]

A. Mixture of helium and oxygen
B. Mixture of neon and oxygen
C. Mixture of xenon and nitrogen
D. Mixture of argon and oxygen
Answer» B. Mixture of neon and oxygen
22.

The compounds of alkaline earth metals have the following magnetic nature [MP PET/PMT 1998; RPMT 2000; JIPMER 2002]

A. Diamagnetic
B. Paramagnetic
C. Ferromagnetic
D. Diaferromagnetic
Answer» B. Paramagnetic
23.

The number of electron and proton in the third alkaline earth metal ion will be [MP PET 2003]

A. \[\frac{e}{20},\,\,\frac{p}{20}\]
B. \[\frac{e}{18},\,\,\frac{p}{20}\]
C. \[\frac{e}{18},\,\,\frac{p}{18}\]
D. \[\frac{e}{19},\,\,\frac{p}{20}\]
Answer» E.
24.

Solubility of iodine in water is greatly increased by the addition of iodide ions because of the formation of ...... [IIT 1994]

A. \[{{I}_{2}}\]
B. \[{{I}_{3}}\]
C. \[{{I}_{3}}^{-}\]
D. \[{{I}^{-}}\]
Answer» D. \[{{I}^{-}}\]
25.

Which of the following statements is false for alkali metals [MNR 1994; MP PET 2001]

A. Lithium is the strongest reducing agent
B. \[Na\] is amphoteric in nature
C. \[L{{i}^{+}}\] is exceptionally small
D. All alkali metals give blue solution in liquid ammonia
Answer» C. \[L{{i}^{+}}\] is exceptionally small
26.

The substance not likely to contain \[CaC{{O}_{3}}\] is [AIEEE 2003]

A. A marble statue
B. Calcined gypsum
C. Sea shells
D. Dolomite
Answer» C. Sea shells
27.

Which group is called buffer group of the periodic table [Pb. CET 2004]

A. I
B. VII
C. VIII
D. Zero
Answer» E.
28.

Which one of the following is not an amphoteric substance [KCET 2004]

A. \[HN{{O}_{3}}\]
B. \[HCO_{3}^{-}\]
C. \[{{H}_{2}}O\]
D. \[N{{H}_{3}}\]
Answer» B. \[HCO_{3}^{-}\]
29.

What is the correct relationship between the pHs of isomolar solutions of sodium oxide \[(p{{H}_{1}}),\] sodium sulphide \[(p{{H}_{2}}),\] sodium selenide \[(p{{H}_{3}})\] and sodium telluride \[(p{{H}_{4}})\] [CBSE PMT 2005]

A. \[p{{H}_{1}}>p{{H}_{2}}=p{{H}_{3}}>p{{H}_{4}}\]
B. \[p{{H}_{1}}<p{{H}_{2}}<p{{H}_{3}}<p{{H}_{4}}\]
C. \[p{{H}_{1}}<p{{H}_{2}}<p{{H}_{3}}=p{{H}_{4}}\]
D. \[p{{H}_{1}}>p{{H}_{2}}>p{{H}_{3}}>p{{H}_{4}}\]
Answer» E.
30.

As the alkaline earth metals (except Be) tend to lose their valence electrons readily they act as [Kerala (Med.) 2002]

A. Weak oxidising agent
B. Weak reducing agent
C. Strong oxidising agent
D. Strong reducing agent
Answer» E.
31.

The correct sequence in decreasing order of the percentage of nitrogen in the given compounds is [NDA 1999]

A. Urea > Ammonium chloride > Ammonium nitrate > Ammonium nitrite
B. Urea > Ammonium nitrate > Ammonium nitrite > Ammonium chloride
C. Urea > Ammonium nitrite > Ammonium nitrate > Ammonium chloride
D. Urea > Ammonium nitrite > Ammonium chloride > Ammonium nitrate
Answer» D. Urea > Ammonium nitrite > Ammonium chloride > Ammonium nitrate
32.

A certain metal M is used to prepare an antacid, which is used as a medicine in acidity. This metal accidently catches fire which can not be put out by using \[C{{O}_{2}}\] based extinguishers. The metal M is [BHU 2002]

A. \[Ca\]
B. C
C. Mg
D. All of these
Answer» D. All of these
33.

The thermal stability of alkaline earth metal carbonates \[MgC{{O}_{3}},\,CaC{{O}_{3}},\]\[BaC{{O}_{3}}\] and \[SrC{{O}_{3}}\]decreases as [MP PMT 2002]

A. \[CaC{{O}_{3}}>SrC{{O}_{3}}>MgC{{O}_{3}}>BaC{{O}_{3}}\]
B. \[BaC{{O}_{3}}>SrC{{O}_{3}}>MgC{{O}_{3}}>CaC{{O}_{3}}\]
C. \[BaC{{O}_{3}}>SrC{{O}_{3}}>CaC{{O}_{3}}>MgC{{O}_{3}}\]
D. \[MgC{{O}_{3}}>CaC{{O}_{3}}>SrC{{O}_{3}}>BaC{{O}_{3}}\]
Answer» D. \[MgC{{O}_{3}}>CaC{{O}_{3}}>SrC{{O}_{3}}>BaC{{O}_{3}}\]
34.

The element having atomic number 56 belongs to [AFMC 2002]

A. Actinides
B. Alkaline earth metals
C. Transition series
D. Lanthanides
Answer» C. Transition series
35.

Which of the following statements is false [BHU 2005]

A. CaOCl2 gives OH-, Cl- and OCl­- in aqueous solution
B. Diamond and graphite are allotrops of carbon
C. Bleaching action of Cl2 in moist condition is not permanent
D. Calomel is Hg2Cl2
Answer» D. Calomel is Hg2Cl2
36.

Which of the following hydroxide is insoluble in water [AIIMS 2001]

A. \[Be{{(OH)}_{2}}\]
B. \[Mg{{(OH)}_{2}}\]
C. \[Ca{{(OH)}_{2}}\]
D. \[Ba{{(OH)}_{2}}\]
Answer» B. \[Mg{{(OH)}_{2}}\]
37.

\[MgC{{l}_{2}}.6{{H}_{2}}O\] when heated gives [CPMT 1997]

A. Magnesium oxychloride
B. Magnesium dichloride
C. Magnesium oxide
D. Magnesium chloride
Answer» D. Magnesium chloride
38.

Which one of the following is the strongest base [Pb. PMT 1998]

A. \[Be{{\left( OH \right)}_{2}}\]
B. \[Mg{{\left( OH \right)}_{2}}\]
C. \[Al{{\left( OH \right)}_{3}}\]
D. \[Si{{\left( OH \right)}_{4}}\]
Answer» C. \[Al{{\left( OH \right)}_{3}}\]
39.

Which of the following alkaline-earth metal hydroxides is the strongest base [CPMT 1996]

A. \[Be{{(OH)}_{2}}\]
B. \[Mg{{(OH)}_{2}}\]
C. \[Ca{{(OH)}_{2}}\]
D. \[Ba{{(OH)}_{2}}\]
Answer» E.
40.

Alkaline earth metals come under [Bihar MEE 1996]

A. Halogens
B. Representative elements
C. Transition elements
D. Inner transition elements
E. None of these
Answer» C. Transition elements
41.

The formula for calcium chlorite is [CBSE PMT 1994, 96]

A. \[Ca{{\left( Cl{{O}_{4}} \right)}_{2}}\]
B. \[Ca{{\left( Cl{{O}_{3}} \right)}_{2}}\]
C. \[CaCl{{O}_{2}}\]
D. \[Ca{{(Cl{{O}_{2}})}_{2}}\]
Answer» E.
42.

A mixture of lime paste is sand, water and [RPMT 1997]

A. Gypsum
B. Slacked lime
C. Quick lime
D. Lime stone
Answer» D. Lime stone
43.

In the Alkaline earth metals, the element forming predominantly covalent compound is [BHU 2001]

A. \[Be\]
B. \[Mg\]
C. \[Sr\]
D. \[Ca\]
Answer» B. \[Mg\]
44.

Which of the following substances is used in the laboratory for fast drying of neutral gases [AIIMS 1998; AFMC 1999]

A. Sodium phosphate
B. Phosphorus pentoxide
C. Sodium sulphate
D. Anhydrous calcium chloride
Answer» E.
45.

Alkaline earth metals are [MP PMT 1996]

A. Li, Be, K, Mg, Ca
B. Be, Mg, Ca, Sr, Ba
C. Be, K, Mg, Ca, Sr
D. Be, Mg, Ca, K, Rb
Answer» C. Be, K, Mg, Ca, Sr
46.

Which of the following decreases on going gradually from \[Be\] to \[Ba\] (in periodic table)

A. Basic character of hydroxides
B. Solubility of sulphates in water
C. Solubility of hydroxides in water
D. Strength of elements as reducing agent
Answer» C. Solubility of hydroxides in water
47.

Identify the correct statement [CBSE PMT 1995]

A. Gypsum contains a lower percentage of plaster of calcium than plaster of paris
B. Gypsum is obtained by heating plaster of paris
C. Plaster of paris can be obtained by hydration of gypsum
D. Plaster of paris is obtained by partial oxidation of gypsum
Answer» B. Gypsum is obtained by heating plaster of paris
48.

Portland cement is manufactured by using [CPMT 1986]

A. Lime stone, clay and sand
B. Lime stone, gypsum and sand
C. Lime stone, gypsum and alumina
D. Lime stone, clay and gypsum
Answer» E.
49.

A major constituent of portland cement except lime is [CPMT 1982]

A. Silica
B. Alumina
C. Iron oxide
D. Magnesia
Answer» B. Alumina
50.

A substance absorbs \[C{{O}_{2}}\] and violently reacts with water. That substance is [AFMC 1988]

A. \[CaC{{O}_{3}}\]
B. \[CaO\]
C. \[{{H}_{2}}S{{O}_{4}}\]
D. \[ZnO\]
Answer» C. \[{{H}_{2}}S{{O}_{4}}\]