1

### JEE Main 2016 (Online) 9th April Morning Slot

Match the items in Column I with its main use listed in Column II :

Column I Column II
(A) Silica gel (i) Transistor
(B) Silicon (ii) Ion-exchanger
(C) Silicone (iii) Drying agent
(D) Silicate (iv) Sealant
A
(A)-(iii), (B)-(i), (C)-(iv), (D)-(ii)
B
(A)-(iv), (B)-(i), (C)-(ii), (D)-(iii)
C
(A)-(ii), (B)-(iv), (C)-(i), (D)-(iii)
D
(A)-(ii), (B)-(i), (C)-(iv), (D)-(iii)

## Explanation

(A)   Silica gel (SiO2) is a good dehydrating agent. It is used good dehydrating agent. It is used to absorb moisture.

SiO2  +   2H2O  $\to$  SiO2  .  2H2O

(B)    Silicon is used in transistor as it is a semiconductor.

(c)   Silicon is a good resistant of heat, water. So it used as sealant to seal some element.

(d)   Silicate including zeolites used in ion-exchange beds in domestic and commercial water purification, softening and other applications.
2

### JEE Main 2016 (Online) 10th April Morning Slot

Aqueous solution of which salt will not contain ions with the electronic configuration 1s22s22p63s23p6 ?
A
NaF
B
NaCl
C
KBr
D
CaI2

## Explanation

NaF is composed of Na+ and F.

Na+ : 1s22s22p6

F- : 1s22s22p6

Hence do not match with the configuration given in the question.
3

### JEE Main 2016 (Online) 10th April Morning Slot

Assertion :     Among the carbon allotropes, diamond is an insulator, whereas, graphite is a good conductor of electricity.

Reason :     Hybridization of carbon in diamond and graphite are sp3 and sp2, respectively.
A
Both assertion and reason are correct, and the reason is the correct explanation for the assertion.
B
Both assertion and reason are correct, but the reason is not the correct explanation for the assertion
C
Assertion is incorrect statement, but the reason is correct.
D
Both assertion and reason are incorrect.

## Explanation

In diamond, each C - atom is covalently bonded with four other carbon atom. So it utilizes its four unpaired electrons in bond formation. Due to this reason diamond is a bad conductor of electricity.

In graphite, each carbon atom is covalently bonded to three carbon atom. In those bond formation 3 out of 4 valence electrons of each C - atom are used while the fourth electron is free to move in the structure of graphite. Due to this reason graphite is a good conductor of electricity.

In diamond, each carbon is bonded with 4 other carbon so, carbon is sp3 hybridized.

In graphite, each carbon is bonded with 3 other carbon so carbon is sp2 hybridized.

So, here both Assertion and Reason are correct but hybridization is not the reason for the Assertion.
4

### JEE Main 2016 (Online) 10th April Morning Slot

Identify the incorrect statement :
A
S2 is paramagnetic like oxygen.
B
Rhombic and monoclinic sulphur have S8 molecules.
C
S8 ring has a crown shape.
D
The S-S-S bond angles in the S8 and S6 rings are the same.

## Explanation

S8 ring has crown shape and bond angle is 107o

S6 ring has chair form hexagon ring and bond angle is 102.2o.