Periodic Table & Periodicity

JEE Chemistry · 270 questions · Page 21 of 27 · Click an option or "Show Solution" to reveal answer

Q201

\text{ Match the LIST-I with LIST-II }

.tg .tg LIST-I (Family) LIST-II (Symbol of Element) A. Pnictogen (group 15) I Ts B Chalcogen II Og C Halogen III Lv D Noble gas IV Mc Choose the correct answer from the options given below:

A A-IV, B-I, C-II, D-III

B A-IV, B-III, C-I, D-II

C A-III, B-I, C-IV, D-II

D A-II, B-III, C-IV, D-I

Correct Answer

Option B

Solution

To correctly match the elements with their respective families and symbols, consider the following associations: Pnictogen is matched with Moscovium (Mc), which has the atomic number 115.

Chalcogen corresponds to Livermorium (Lv), with the atomic number 116.

Halogen is associated with Tennessine (Ts), with atomic number 117.

Noble gas correlates with Oganesson (Og), which has an atomic number of 118.

This alignment clarifies the classification of elements based on their family groups and chemical symbols.

Q202

Match List I with List II : .tg .tg List I List II A. Slaked lime I.

\mathrm{NaOH}

B. Dead burnt plaster II.

\mathrm{Ca(OH)_2}

C. Caustic soda III.

\mathrm{Na_2CO_3\cdot 10H_2O}

D. Washing soda IV.

\mathrm{CaSO_4}

Choose the correct answer from the options given below :

A (A) - III, (B) - IV, (C) - II, (D) - I

B (A) - III, (B) - II, (C) - IV, (D) - I

C (A) - II, (B) - IV, (C) - I, (D) - III

D (A) - I, (B) - IV, (C) - II, (D) - III

Correct Answer

Option C

Solution

A : Slaked lime $\quad: \mathrm{Ca}(\mathrm{OH})_{2}$ B : Dead burnt plaster $\quad$ : $\mathrm{CaSO}_{4}$ C : Caustic Soda $\quad$ : $\mathrm{NaOH}$ D : Washing Soda $\quad$ : $\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot 10 \mathrm{H}_{2} \mathrm{O}$

Q203

Three elements X, Y and Z are in the 3rd period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is :

A X < Z < Y

B Y < X < Z

C Z < Y < X

D X < Y < Z

Correct Answer

Option D

Solution

When we are moving from left to right in a periodic table along with atomic number of atom acidic character of oxides also increases. $\therefore$ atomic number : X < Y < Z then acidic character : X < Y < Z

Q204

The first ionization energy (in kJ/mol) of Na, Mg, Al and Si respectively, are :

A 496, 577, 786, 737

B 496, 737, 577, 786

C 786, 737, 577, 496

D 496, 577, 737, 786

Correct Answer

Option B

Solution

Elecronic configuration of Na = [Ne] 3s1 Mg = [Ne] 3s2 Al = [Ne] 3s23p1 Si = [Ne] 3s23p2 Correct order is : Na

<

<

<

Q205

KO2 (potassium super oxide) is used in oxygen cylinders in space and submarines because it :

A absorbs CO2 and increases O2 content

B eliminates moisture

C absorbs CO2

D produces ozone

Correct Answer

Option A

Solution

2K{O_2} + 2{H_2}O

\to 2KOH + {H_2}{O_2} + {O_2}

K{O_2}

is used as an oxidising agent.

It is used as air purifier in space capsules.

Submarines and breathing masks as it produces oxygen and removes carbon dioxide.

Q206

Among the following, the energy of 2s orbital is lowest in :

A Li

B H

C Na

D K

Correct Answer

Option D

Solution

Here Z of K = 15, Na = 11, H = 1, Li = 3.

In K, because of more number of protons (high atomic number) the 2s electron experiences a higher effective nuclear charge and is closer to nucleus, thus having less energy

Q207

The increasing order of the first ionization enthalpies of the elements B, P, S and F (lowest first) is :

A F < S < P < B

B P < S < B < F

C B < P < S < F

D B < S < P < F

Correct Answer

Option D

Solution

The correct order of ionisation enthalpies is

F > P > S > B

NOTE : On moving along a period ionization enthalpy increases from left to right and decreases from top to bottom in a group.

But this trend breaks up in case of atom having fully or half filled stable orbitals.

In this case

P

has a stable half filled electronic configuration hence its ionisation enthalpy is greater in comparison to

S.

For B(5) electronic configuration is = 1s22s22p1 and P(15) electronic configuration is = 1s22s22p63s23p3.

As P has half filled valence shell so removing electron will be harder compare to B.

Hence by checking all options the correct possible order is B < S < P < F

Q208

The following statements concern elements in the periodic table. Which of the following is true ?

A All the elements in Group 17 are gases.

B The Group 13 elements are all metals.

C Elements of Group 16 have lower ionization enthalpy values compared to those of Group 15 in the corresponding periods.

D For Group 15 elements, the stability of + 5 oxidation state increases down the group.

Correct Answer

Option C

Solution

(A) Group 17 elements are halogens; they exist in all three states of matter at room temperature.

(B) Except for the lightest element (boron), all other Group 13 elements are relatively electropositive and are thus metals.

(C) Group 15 elements have half-filled electronic configuration, thus have high values of ionization enthalpy, while Group 16 elements achieve halffilled configuration on loss of one electron and therefore have lower ionisation enthalpy. (i) In Group 15 elements, due to the inert pair affect the stability of +5 oxidation state decreases down the group.

Q209

When the first electron gain enthalpy

\left( {{\Delta _{eg}}H} \right)

of oxygen is

-

141 kJ/mol, its second electron gain enthalpy is :

A a more negative value than the first

B almost the same as that of the first

C negative, but less negative than the first

D a positive value

Correct Answer

Option D

Solution

Second electron gain enthalpy is always positive for every element. O $-$ (g) + e $-$ $\to$ O $-$ 2(g) ;

\Delta

H = positive

Q210

According to the Periodic Law of elements, the variation in properties of elements is related to their

A nuclear masses

B atomic numbers

C nuclear neutron-proton number ratios

D atomic masses

Correct Answer

Option B

Solution

According to modified modern periodic law, physical and chemical properties of the elements are periodic functions of their atomic numbers.

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