Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is:
1. | F > Cl > Br > I | 2. | F < Cl < Br < I |
3. | F < Cl > Br > I | 4. | F < Cl < Br > I |
The formation of oxide ion O2-(g), from oxygen atom, requires first an exothermic and then an endothermic step as shown below
Thus, the process of formation of O2- in the gas phase is unfavourable even though O2- is isoelectronic with neon. It is due to the fact that:
1. | Oxygen is more electronegative |
2. | Addition of electron in oxygen results in a larger size of the ion |
3. | Electron repulsion outweighs the stability gained by achieving noble gas configuration |
4. | O- ion has comparatively smaller size than oxygen atom |
Electronic configuration of four elements A, B, C and D are given below :
A.
B.
C.
D.
The correct order of increasing tendency to gain electron is :
1. | A < C < B < D | 2. | A < B < C < D |
3. | D < B < C < A | 4. | D < A < B < C |
Match the correct ionization enthalpies and electron gain enthalpies of the following elements.
Elements |
|
|
|
||
(i) |
Most reactive non-metal |
A. |
419 |
3051 |
-48 |
(ii) |
Most reactive metal |
B. |
1681 |
3374 |
-328 |
(iii) |
Least reactive element |
C. |
738 |
1451 |
-40 |
(iv) |
Metal forming binary halide |
D. |
2372 |
5251 |
+48 |
Codes
A | B | C | D | |
1. | ii | i | iv | iii |
2. | i | ii | iii | iv |
3. | i | iv | iii | ii |
4. | iv | i | iii | ii |
Electronic configuration of some elements is given in Column I and their electron gain enthalpies are given in Column II. Match the electronic configuration with electron gain enthalpy.
Column I (Electron configuration) |
Column II (Electron gain enthalpy/kJ mol–1) |
||
A. | 1. |
–53 |
|
B. | 2. |
–328 |
|
C. | 3. |
–141 |
|
D. | 4. |
+48 |
Codes:
Options: | A | B | C | D |
1. | 4 | 1 | 2 | 3 |
2. | 1 | 2 | 3 | 5 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |
Assertion (A): | Generally, ionisation enthalpy increases from left to right in a period. |
Reason (R): | When successive electrons are added to the orbitals in the same principal quantum level, the shielding effect of inner core of electrons does not increase very much to compensate for the increased attraction of the electron to the nucleus. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Given below are two statements:
Assertion (A): | Electron gain enthalpy becomes less negative as we go down a group. |
Reason (R): | The size of the atom increases on going down the group and the added electron would be farther from the nucleus. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
An element(s) that gain one electron more readily in comparison to other elements of their group is/are:
(a) S(g)
(b) Na(g)
(c) O(g)
(d) Cl(g)
Choose the correct option:
1. (a), (d)
2. (b), (c)
3. (c), (d)
4. (b), (d)
Correct statement(s) among the following are:
(a) | Helium has the highest first ionisation enthalpy in the periodic table. |
(b) | Chlorine has less negative electron gain enthalpy than fluorine. |
(c) | Mercury and bromine are liquids at room temperature. |
(d) | In any period, the atomic radius of alkali metal is the highest. |
Choose the correct option:
1. (a), (c), (d)
2. (a), (b), (c)
3. (a), (c)
4. (a), (d)