31 Year NEET Previous Year Questions: The p-Block Elements - 1 - NEET MCQ

Bond dissociation energy of fluorine is less because of its small size and repulsion between electrons of two atoms. So option (c) is wrong order. The correct order is [Cl₂ > Br₂ > F₂ > I₂]

As the oxidation number of the central atom increases, strength of acid also increases.

From the given options we find option (a) is correct. The oxidising power of halogens follow the order F₂ > Cl₂ > Br₂ > I₂ . Option (b) is incorrect because it in not the correct order of electron gain enthalpy of halogens. The correct order is Cl₂ > F₂ > Br₂ > I₂ . The low value of F2 than Cl2 is due to its small size. Option (c) is incorrect. The correct order of bond dissociation energies of halogens is Cl₂ > Br₂ > F₂ > I₂ . Option (d) is correct. It is the correct order of electronegativity values of halogens. Thus option (b) and (c) are incorrect.

MI > MBr > MCl > MF. As the size of the anion decreases covalency decreases.

Standard reduction potential of halogens are positive and decreases from fluorine to iodine. Therefore halogens act as strong oxidising agent and their oxidising power decreases from fluorine to iodine.

The correct order of increasing bond angle is   

* In ClO₂^– there are 2 lone pairs of electrons present on the central chlorine atom. Therefore the bond angle in ClO₂^– is less than 118° which is the bond angle in ClO₂ which has less number of electrons on chlorine.

The correct answer is Option D.

H₄P₂O₅ ;
​4+2x−10=0                           
​2x=6
x= +3 
 
H₄P₂O₆ ; 
4+2x−12=0
2x=8   
x= +4
 
H₄P₂O₇ 
4+2x−14=0                     
2x=10                                                           
 x= +5
 

KO2 is known as potassium superoxide. It is paramagnetic in nature. It is formed by the direct reaction of oxygen gas and potassium metal. ... BaO2 is a peroxide because in BaO2 the oxidation state of barium is +2 and oxygen has oxidation number −1.

(a) Sulphuric acid (iv) Contact process
(b) Steel (ii) Bessemer ’s process
(c) Sodium hydroxide(iii) Leblanc process
(d) Ammonia (i) Haber ’s process
∴ Correct choice : (a)

∴ Correct choice : (b)

Formal charges help in the selection of the lowest energy structure from a number of possible Lewis structures for a given compound. The lowest energy structure means the structure with the smallest formal charge on each atom of the compound. A Lewis dot structure is preferable when all formal charges are zero.

SnO₂ is an amphoteric oxide because it reacts with acids as well as bases to form corresponding salts.

Thus, nitrogen exhibits highest oxidation state in N₃H
Thus question can also be credited to redox reactions 

Hypophosphorous acid

(H₃PO₂) is a monobasic acid. i.e., it has only one ionisable hydrogen atom or one OH is present

HClO₄ is the strongest acid amongst all because the oxidation state or Cl is maximum (+7).

SF₄ has 4 bond pairs and 1 lone pair of electrons, sp³d hybridisation leads to irregular shapeand resultant

μ ≠ 0.

If acidic nature is high, K_a is high and pk_a is low

since pk_a = – log k_a
Hence the order of pka will be H₂O > H₂S > H₂Se > H₂Te