Assertion (A):	Fluorine forms only one oxoacid, HOF.
Reason (R):	Fluorine has a small size and high electronegativity.

 

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	Both (A) and (R) are True and (R) is not the correct explanation of (A).
3.	(A) is True but (R) is False.
4.	(A) is False but (R) is True.

The correct order among the following options is: 

1. F > N > C > Si > Ga - Non-metallic character

2. F > O> Cl >N - Oxidising property

3. C < Si > P > N  - Electron affinity value

4. All of the above

The electron gain enthalpies of halogens in kJ mol^-1 are given below.

F =-332, Cl =-349, Br =-325, I =-295.

The lesser negative value for F as compared to that of Cl is due to:
 

1. Strong electron-electron repulsions in the compact 2p-subshell of F.

2. Weak electron-electron repulsions in the bigger 3p-subshell of Cl.

3. Smaller electronegativity value of F than Cl.

4. 1 & 2 both 

Given below are four orders for the size of the species. Choose the correct ones:

(a) ${\mathrm{Al}}^{3+}<{\mathrm{Mg}}^{2+}<{\mathrm{Na}}^{+}<{\mathrm{F}}^{-}$

(b) ${\mathrm{Al}}^{3+}<{\mathrm{Mg}}^{2+}<$ ${\mathrm{Li}}^{+}<{\mathrm{K}}^{+}$

(c) ${\mathrm{Fe}}^{4+}<{\mathrm{Fe}}^{3+}<{\mathrm{Fe}}^{2+}<\mathrm{Fe}$

(d) $\mathrm{Mg}>\mathrm{Al}>\mathrm{Si}>\mathrm{P}$

1. (a), (b) & (c)                       

2. (b), (c) & (d)

3. (a), (c)                          

4. (a), (b), (c) & (d)

Incorrect statement about characteristics regarding halogens is :

1. Ionization energy decreases with increase in atomic number.

2. Electronegativity decreases with increase in atomic number.

3. Electron affinity decreases with increase in atomic number.

4. Enthalpy of fusion increases with increase in atomic number. 

${\mathrm{IP}}_1$ and ${\mathrm{IP}}_2$ for Mg are 178 Kcal mol^–1 and 348 Kcal ${\mathrm{mol}}^{-1}$, respectively. The energy required for the reaction, $\mathrm{Mg}\to {\mathrm{Mg}}^{2+}$ $+$ $2{\mathrm{e}}^{-}$ will be:

1. +170 Kcal ${\mathrm{mol}}^{-1}$

2. +526 Kcal ${\mathrm{mol}}^{-1}$

3. –170 Kcal ${\mathrm{mol}}^{-1}$

4. –526 Kcal ${\mathrm{mol}}^{-1}$

The incorrect match among the following options is:

If the ionization enthalpy and negative electron gain enthalpy of an element are 275 and 86 kcal $mo{l}^{-1}$ respectively, then the electronegativity of the element on the Pauling scale is:

1. 2.8                                     

2. 0.0

3. 4.0                                     

4. 2.6

First three ionisation energies (in kJ/mol) of three representative elements are given below:

Element     $I{E}_1$                    $I{E}_2$                   $I{E}_3$

P               495.8                4562                  6910
Q               737.7               1451                   7733
R               577.5                1817                  2745

Then incorrect option is :

1. Q: Alkaline earth metal.

2. P: Alkali metal.

3. R: s-block element.

4. All three: P,Q & R belong to the same period.

In alkaline earth metals, the properties, from the following, that will increase from Be to Ba are-

(i) Atomic radius       
(ii) Ionisation energy       
(iii) Nuclear charge