JEE Previous Year Questions- p-Block Elements with solutions - Free MCQ

The correct answer is option A (3,2,1)
XeF_2​ has a linear shape. Its hybridization is sp3d which means it should have a trigonal bipyramidal shape. Since it has 3 lone pairs, they occupy the equatorial triangle.
XeF₄​ has sp³d² hybridization. It has a square planar shape and 2 lone pairs of electrons.
XeF₆​ has one lone pair of electrons. The 6 out of 8 electrons of Xenon are shared by 6 atoms of fluorine.

16 σ bonds are present

The correct answer is option A
Molecular formula of Hypophosphorous Acid is H3​PO2​. 
In this, two hydrogen atoms are attached to phosphorus atom with single bond, one -OH group is attached to phosphorus atom with single bond and one oxygen atom is attached to phosphorus atom with double bond.

Helium is twice as heavy as hydrogen and Helium is not lighter than hydrogen; its lifting power is 92% of that of hydrogen. Helium has the lowest melting and boiling point of any element which makes liquid helium an ideal coolant for many extremely low temperature application such as super conducting magnet and cryogenic research where temperature close to absolute zero are needed.

Hence C

XeO3​+6HF⟶XeF6​+3H2​O

This reaction is not feasible because the products again react to give reactants back. All the xenon fluorides easily undergo hydrolysis and give xenon oxides but the opposite is not possible.

Hence D

The correct answer is Option B.
In group15 hydrides, the basic character decreases on going down the group due to decrease in the availability of the lone pair of electrons because of the increase in size of elements from N to Bi. Thus, correct order of basicity is:
NH₃ > PH₃ > AsH₃ > SbH₃.
 

The correct answer is option C
Layer of O₃ in the upper atmosphere absorbs UV radiations from the sun, thus protecting the human being living on the earth.
Nitrogen oxides (particularly nitric oxide) combine very rapidly with ozone and there is, thus, the possibility that nitrogen oxides emitted from the exhaust systems of supersonic jet aeroplanes might be slowly depleting the concentration of the ozone layer in the upper atmosphere.
The use of chlorofluorocarbon in aerosol and refrigerator and there, subsequent escape into the atmosphere is responsible for making holes in the ozone layer. Ozone at all does not absorb infrared radiation.

CaC₂ has a combination of bonds. It is an ionic lattice that has Ca(2+) cations and acetylide C2(2-) anions. Within each C₂(2-), there is a triple bond between the 2 C atoms, consisting of 1 sigma and 2 pi bonds.