Question

Class 11 chemistry MCQ Question of Classification of Elements and Periodicity in Properties with Answers?

Answer 1

The periodic table is an efficient plan of the arrangement of known chemical elements. In the advanced periodic table, the atoms are arranged with the expanding atomic number. There is a sure noticeable periodic pattern of physical and chemical properties of components in a gathering through and through and in a period when we move from left to right. 

We have given MCQ Questions to Class 11 Chemistry with Answers to assist understudies with understanding the idea score great marks on exams. Class 11 Chemistry MCQ Questions of Classification of Elements and Periodicity in Properties with Answers were arranged dependent on the most recent exam pattern. Learn these MCQ Questions for Class 11 Chemistry Classification of Elements and Periodicity in Properties with Answers and clear all concepts patterns of Questions asked in exams.
 

Practice MCQ Questions for class 11 Chemistry Chapter-Wise

1. The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups. Its reason is:

(a) Both are found together in nature
(b) Both have nearly the same size
(c) Both have similar electronic configuration
(d) diagonal relationship

2. The correct order of first ionization potential among following elements, Be, B, C, N and O is

(a) B < Be < C < O < N
(b) B < Be < C < N < O
(c) Be < B < C < N < O
(d) Be < B < C < O < N

3. Representative elements are those which belong to

(a) p and d – Block
(b) s and d – Block
(c) s and p – Block
(d) s and f – Block

4. Which of the following properties generally decreases along a period?

(a) Ionization Energy
(b) Metallic Character
(c) Electron Affinity
(d) Valency

5. On the Paulings electronegativity scale the element next to F is

(a) N
(b) Cl
(c) O
(d) Ne

6. Which of the following oxides is amphoteric in character?

(a) SnO₂
(b) CO₂
(c) SiO₂
(d) CaO

7. In the modern periodic table, the period indicates the value of:

(a) Atomic Number
(b) Atomic Mass
(c) Principal Quantum Number
(d) Azimuthal Quantum Number

8. In the long form of the periodic table, the valence shell electronic configuration of 5s²5p4 corresponds to the element present in:

(a) Group 16 and period 6
(b) Group 17 and period 6
(c) Group 16 and period 5
(d) Group 17 and period 5

9. l, Br, I, if this is Dobereiner’s triad and the atomic masses of Cl and I are 35.5 and 127 respectively the atomic mass of Br is

(a) 81.25
(b) 162.5
(c) 91.5
(d) 45.625

10. If the two members of a Dobereiner triad are phosphorus and antimony, the third member of this triad is

(a) arsenic
(b) iodine
(c) sulphur
(d) calcium

11. Johann Doberiner gave the idea of trends among physical and ...X... of several groups of three elements. Here, X refers to

(a) chemical properties
(b) atomic number
(c) atomic mass
(d) None of these

12. Newlands could classify elements only upto

(a) calcium
(b) copper
(c) chlorine
(d) chromium

13. At present, how many elements are known

(a) 118
(b) 112
(c) 110
(d) 113

14. Which of the scientists given below discovered that periodic table should be based on the atomic number?

(a) Moseley
(b) Mendeleev
(c) Newlands
(d) Lothar Meyer

15. How many elements are there in 6th period of periodic table?

(a) 32
(b) 8
(c) 18
(d) 30

16. Modern periodic table is based on the atomic number of the elements. The experiment which proved the significance of the atomic number was

(a) Mosley’s work on X-ray spectra
(b) Bragg’s work on X-ray diffraction
(c) Discovery of X-rays by Rontgen
(d) Mulliken’s oil drop experiment

17. Which of the following ion will form most water soluble hydroxide?

(a) K⁺
(b) Ni²⁺
(c) Zn²⁺
(d) Al³⁺

18. Which of the following has greatest tendency to lose electron?

(a) F
(b) Fr
(c) S
(d) Be

19. Gradual addition of electronic shells in the noble gases causes a decrease in their

(a) Ionization energy
(b) atomic radius
(c) Boiling point
(d) density

20. Which of the following has highest first ionization potential?

(a) Carbon
(b) Oxygen
(c) Nitrogen
(d) Boron

21. Electron affinity depends on

(a) Atomic size
(b) Nuclear charge
(c) Atomic number
(d) Atomic size and nuclear charge both

22. On electrolysis of NaH, hydrogen is liberated

(a) At anode
(b) in the electrolyte
(c) At cathode
(d) none of them

23. What is the symbol of the element with only three electrons and three protons?

(a) Li
(b) C
(c) Ag
(d) Cu

24. Which one of the following is not a coinage metal?

(a) Au
(b) Cu
(c) Ag
(d) Pd

25. Eka aluminium and Eka silicon are now known as:

(a) Ga and Ge
(b) Al and Si
(c) Fe and S
(d) H⁺ and Si

Answer 2

1. Answer : (d) diagonal relationship

Explanation: The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups because of diagonal relationship.

2. Answer : (a) B < Be < C < O < N

Explanation: The amount of energy required to remove an electron from the outermost orbit of a gaseous atom is known as ionisation potential. Elements having half-filled or completely filled' orbitals are more stable than partially filled orbitals. In a period from left to right ionisation potential decreases as the atomic number increases. The given elements (Be, B, C, N, O) are present in II period as Be < B< C < N < O. But in case of Be and B, Be has higher ionisation potential due to stable configuration So, the correct order of increasing ionisation potential will be B < Be < C < O <N

3. Answer : (c) s and p – Block

Explanation: The representative elements are all the elements in groups one, two, thirteen, fourteen, fifteen, sixteen, seventeen and eighteen of the periodic table. These include metals, non metals and semi metals (metalloid).

4. Answer : (b) Metallic Character

Explanation: Along a period the electropositive character decreases, therefore the ionization energy, electron affinity and valency increases while metallic character decreases.

5. Answer : (c) O

Explanation: According to Pauling's electronegativity scale, oxygen (O) has an electronegativity value of approximately 3.5, which is next to fluorine (F) with electronegativity value of approximately 4.

6. Answer : (a) SnO₂

Explanation: A species is amphoteric if it is soluble in acid (behaves as a base) as well as in base (behaves as an acid).

SnO₂ + 4HCl → SnCl₄ + 2H₂O

SnO₂ + NaOH→ Na₂SnO₃ + H₂O

7. Answer : (c) Principal Quantum Number

Explanation: In the modern periodic table, each period begins with the filling of a new shell. Therefore, the period indicates the value of principal quantum number.

8. Answer : (c) Group 16 and period 5

Explanation: ns²np⁴ → VI A group

16^th  group, n = 5 (5^th period)

9. Answer : (a) 81.25

Explanation: According to Dobereneir's triads, the atomic mass of Br will be average of the atomic masses of CI & I.

\(=\frac{35.5+127}{2}\)

= 81.25

10. Answer : (a) arsenic

Explanation: According to Dobereiner, the atomic mass of the middle element was nearly equal to the arithmetic mean of the other two. Therefore, the atomic mass of the third element is \(=\frac{31+121.75}{2}\) = 76.37 which is nearly equal to the atomic mass of arsenic.

11. Answer :(a) chemical properties

Explanation: Johann Dobereiner in early 1800's was the first to consider the idea of trends among properties of elements. By 1829 he noted a similarity among the physical and chemical properties of several groups of three elements (triads).

12. Answer : (a) calcium

Explanation: He could classify only elements upto calcium, out of 56 known elements at his time. In order to fit in his table, He kept 2 elements in one slot which may differ in property. Some similar properties elements were separated far apart.

13. Answer : (a) 118

Explanation:  At present, 118 elements are known to us. All these have different properties. Out of these 118, only 94 are naturally occurring.

14. Answer : (a) Moseley

Explanation: It was Henry Moseley who suggested a better arrangement than Mendeleev. He arranged the elements according to their Atomic Number rather than their Atomic mass.

15. Answer : (a) 32

Explanation: The sixth period contains 32 elements, tied for the most with period 7, beginning with caesium and ending with radon. Lead is currently the last stable element; all subsequent elements are radioactive.

16. Answer : (a) Mosley’s work on X-ray spectra

Explanation: Henry Moseley observed regularities in the characteristic X-ray spectra of the elements by plotting square root of frequency of x-rays against atomic number which gave a straight line.

17. Answer : (a) K⁺

Explanation: K⁺ ion will form most water soluble hydroxide because it is the most reactive of these metals and thus forms strong alkali KOH which will undergo complete dissociation in water, thus making it highly soluble.

18. Answer : (b) Fr

Explanation: Francium belongs to alkaline earth metals having one electron in outermost shell. After losing an electron it will acquire noble gas configuration , so it has the maximum tendency to lose an electron.

19. Answer : (a) Ionization energy

Explanation: Gradual addition of electronic shells in the noble gases causes a decrease in their ionisation energy. On moving down the group, number of shells and atomic radius increases. Shielding of outer electrons by inner electrons increases. This decreases the force of attraction between outermost electrons and nucleus. Effective nuclear charge and ionisation enthalpy decreases.

20. Answer : (c) Nitrogen

Explanation: Nitrogen has the highest first ionization energy, though it should have less than that of oxygen while going across a period. The electronic configuration of nitrogen is 1s²,2s²,2px¹,2py¹,2pz¹.Nitrogen has three electrons in 2p subshell which are singly filled. So, nitrogen is in a stable state and does not want to lose electrons. Hence, it has the highest first ionization energy.

21. Answer : (d) Atomic size and nuclear charge both

Explanation: Electron affinity is the amount of energy released when an electron is added to a neutral atom to form a negative ion. EA decreases on moving down the group as the atomic size increases and net nuclear charge increase is offset by extra screening electrons as the additional electron enters an orbital away from the nucleus. So, it is less attracted to nucleus and would release less energy when added.

22. Answer : (a) At anode

Explanation: Hydrogen gas is liberated at the anode as sodium hydride exists as sodium cation and hydride anion. Therefore hydrogen gas is liberated at anode by lose of electrons at anode (oxidation).

23. Answer : (a) Li

Explanation: Lithium is the element that is atomic number 3 on the periodic table. That means each atom contains 3 protons. Lithium is a soft, silvery, light alkali metal denoted with the symbol Li.

24. Answer : (d) Pd

Explanation: The coinage metal comprise, at a minimum, those metallic chemical elements which have historically been used as components in alloys used to mint coins.

25. Answer : (a) Ga and Ge

Explanation: Mendeleev name unnamed elements as EKA- Boron EKA- Aluminium and EKA Silicon which were later replaced as Scandium, Gallium, and germanium respectively. .Eka aluminum is the element Gallium. Eka silicon – It is the element Germanium.

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