11th Chemistry MCQ Collection

 

Chemistry   

Chemistry 11th Standard Multiple Choice Questions With Answers

1) A sample of pure water, whatever the source always contains ___________ by mass of oxygen and 11.1% by mass of hydrogen.

A) 88.8

B) 18

C) 80

D) 16

Ans : 88.8

2) Which of the following compounds can not demonstrate the law of multiple proportions?

A) NO, NO2

B) CO, CO2

C) H2O, H2O2

D) Na2S, NaF

Ans : Na2S, NaF

3) Which of the following temperature will read the same value on celsius and Fahrenheit scales.

A) - 40°

B) + 40°

C) - 80°

D) - 20°

Ans : - 40°

4) SI unit of the quantity electric current is __________

A) Volt

B) Ampere

C) Candela

D) Newton

Ans : Ampere

5) Which of the following has maximum number of molecules?

A) 7gN2

B) 2gH2

C) 8gO2

D) 20gNO2

Ans : 2gH2

6) How many g of H2O are present in 0.25 mol of it?

A) 4.5

B) 18

C) 0.25

D) 5.4

Ans : 4.5

7) The number of molecules in 22.4 cm3 of nitrogen gas at STP is

A) 6.022 × 1020
B) 6.022 × 1023
C) 22.4 × 1020

D) 22.4 × 1023

Ans : 6.022 × 1020

8) Which of the following has the largest number of atoms?

A) 1g Au (s)

B) 1g Na (s)

C) 1g Li (s)

D) 1g Cl2 (g)

Ans : 1g Li (s)

9) The branch of chemistry which deals with study of separation, identification, and quantitative determination of the composition of different substances is called as __________

A) Physical chemistry
B) Inorganic chemistry
C) Organic chemistry
D) Analytical chemistry

Ans : Analytical chemistry

10) Which one of the following property of matter is Not quantitative in nature?

`

A) Mass

B) Length

C) Colour

D) Volume

Ans : Colour

11) SI unit of mass is _________

A) kg

B) Mol

C) Pound

D) M3

Ans : kg

12) The number of significant figures in 1.50 × 104 g is __________

A) 2

B) 3

C) 4

D) 6

Ans : 3

13) In Avogadro’s constant 6.022 × 1023 mol-1, the number of significant figures is ________

A) 3

B) 4

C) 5

D) 6

Ans : 4

14) By decomposition of 25 g of CaCO3, the amount of CaO produced will be

________

A) 2.8 g

B) 8.4 g

C) 14.0 g

D) 28.0 g

Ans : 14.0 g

15) How many grams of water will be produced by complete combustion of 12 g of methane gas

A) 16

B) 27

C) 36

D) 56

Ans : 27

16) Two elements A (At. mass 75) and B (At. mass 16) combine to give a compound having 75.8 % of A. The formula of the compound is

A) AB

B) A2B

C) AB2

D) A2B3

Ans : A2B3

17) The hydrocarbon contains 79.87% carbon and 20.13% of hydrogen. What is its empirical formula?

A) CH

B) CH2

C) CH3

D) C2H5

Ans : CH3

18) How many grams of oxygen will be required to react completely with 27 g of Al? (Atomic mass: Al = 27, O = 16)

A) 8

B) 16

C) 24

D) 32

Ans : 24

19) When two properties of a system are mathematically related to each other, the relation can be deduced by

A) Working out mean deviation

B) Plotting a graph

C) Calculating relative error

D) All the above three

Ans : Plotting a graph

20) Which of the following methods can be used to separate two compounds with different solubilities in the same solvent?

A) Fractional crystallization

B) Crystallization

C) Distillation

D) Solvent extraction

Ans : Fractional crystallization

21) Which of the following techniques is used for the separation of glycerol from soap in the soap industry?

A) Distillation under reduced pressure

B) Fractional distillation

C) Filtration

D) Crystallization

Ans : Distillation under reduced pressure

22) Which technique is widely used in industry to separate components of the mixture and also to purify them?

A) Steam distillation

B) Chromatography

C) Solvent extraction

D) Filtration

Ans : Chromatography

23) A mixture of acetone and benzene can be separated by the following method:

A) Simple distillation

B) Fractional distillation

C) Distillation under reduced pressure

D) Sublimation

Ans : Fractional distillation

24) Colourless components on chromatogram can not be observed by the following:

A) Using UV light

B) Using iodine chamber

C) Using the spraying reagent

D) Using infrared light

Ans : Using infrared light

25) The energy difference between the shells goes on ________ when moved away from the nucleus.

A) Increasing

B) Decreasing

C) Equalizing

D) Static

Ans : Decreasing

26) p-orbitals are _________ in shape.

A) Spherical

B) Dumbbell

C) Double dumbbell

D) Diagonal

Ans : Dumbbell

27) No two electrons in the same atoms can have identical set of four quantum numbers”. This statement is known as -

A) Pauli’s exclusion principle

B) Hund’s rule

C) Aufbau rule

D) Heisenberg uncertainty principle

Ans : Pauli’s exclusion principle

28) Principal Quantum number describes -

A) Shape of orbital

B) Size of the orbital

C) Spin of electron

D) Orientation of in the orbital electron cloud

Ans : Size of the orbital

29) Which molecule is linear?

A) SO3

B) CO2

C) H2S

D) Cl2O

Ans : CO2

30) Which O2 molecule is paramagnetic. It is explained on the basis of:

A) Hybridization

B) VBT

C) MOT

D) VSEPR

Ans : MOT

31) The angle between the two covalent bonds is minimum in:

A) CH4

B) C2H2

C) NH3

D) H2O

Ans : H2O

32) Oxidation number of carbon in H2CO3 is

A) +1

B) +2

C) +3

D) +4

Ans : +4

33) Which of the following halogens does always show oxidation state -1?

A) F

B) Cl

C) Br

D) I

Ans : F

34) In the modern periodic table, the period number indicates the:

A) Atomic number

B) Atomic mass

C) Principal quantum number

D) Azimuthal quantum number

Ans : Principal quantum number

35) The lanthanides are placed in the periodic table at

A) Left-hand side

B) Right-hand side

C) Middle

D) Bottom

Ans : Bottom

36) In which group of elements of the modern periodic table are halogen placed?

A) 17

B) 6

C) 4

D) 2

Ans : 17

37) Which of the atomic number represent the s-block elements?

A) 7, 15

B) 3, 12

C) 6, 14

D) 9, 17

Ans : 3, 12

38) Which of the following pairs is NOT isoelectronic?

A) Na⊕ and Na

B) Mg2⊕ and Ne

C) Al3⊕ and B3⊕

D) P3Θ and N3Θ

Ans : Mg2⊕ and Ne

39) Which of the following pair of elements has similar properties?

A) 13, 31

B) 11, 20

C) 12, 10

D) 21, 33

Ans : 13, 31

40) The unstable isotope of hydrogen is _________

A) H-1

B) H-2

C) H-3

D) All the three

Ans : H-3

41) Identify the odd one.

A) Rb

B) Ra

C) Sr

D) Be

Ans : Rb

42) Which of the following is Lewis acid?

A) BaCl2

B) KCl

C) BeCl2

D) LiCl

Ans : BeCl2

43) What happens when crystalline Na2CO3 is heated?

A) Releases CO2

B) Loses H2O

C) Decomposes in NaHCO3

D) No change taken place

Ans : Loses H2O

44) Which of the following is not an allotrope of carbon?

A) Buckyball

B) Diamond

C) Graphite

D) Emerald

Ans : Emerald

45) _________ is inorganic graphite.

A) Borax

B) Diborane

C) Boron nitride

D) Colemanite

Ans : Boron nitride

46) Haber’s process is used for preparation of _______

A) HNO3

B) NH3

C) NH2CONH2

D) NH4OH

Ans : NH3

47) Thallium shows different oxidation state because __________

A) Of inert pair effect

B) It is inner transition element

C) It is metal

D) Of its high electronegativity

Ans : Of inert pair effect

48) Which of the following shows the most prominent inert pair effect?

A) C

B) Si

C) Ge

D) Pb

Ans : Pb

49) The unit of viscosity is

A) Dynes

B) Newton

C) Gram

D) Poise

Ans : Poise

50) Interactive forces are __________ in an ideal gas.

A) Nil

B) Small

C) Large

D) Same as that of real gases

Ans : Nil