1
MCQ (Single Correct Answer)

NEET 2013

The basic structural unit of silicates is
A
SiO32$$-$$
B
SiO$$_4^{2 - }$$
C
SiO$$-$$
D
SiO$$_4^{4 - }$$

Explanation

SiO$$_4^{4 - }$$ orthosilicate is basic unit of silicates.
2
MCQ (Single Correct Answer)

NEET 2013

Which of these is not a monomer for a high molecular mass silicone polymer?
A
Me3SiCl
B
PhSiCl3
C
MeSiCl3
D
Me2SiCl2

Explanation

Since Me3SiCl contains only one Cl, therefore it can’t form high molecular mass silicon polymer. It can form only dimer.
3
MCQ (Single Correct Answer)

AIPMT 2012 Mains

In which of the following arrangements the given sequence is not strictly according to the property indicated against it?
A
HF < HCl < HBr < HI : increasing acidic strength
B
H2O < H2S < H2Se < H2Te : increasing pKa values
C
NH3 < PH3 < AsH3 < SbH3 : increasing acidic character
D
CO2 < SiO2 < SnO2 < PbO2 : increasing oxidising power

Explanation

If acidic nature is high, Ka is high and pKa is low.

since pKa = – log Ka

Hence the order of pKa will be

H2O > H2S > H2Se > H2Te
4
MCQ (Single Correct Answer)

AIPMT 2012 Prelims

Sulphur trioxide can be obtained by which of the following reaction?
A
CaSO4 + C $$\buildrel \Delta \over \longrightarrow $$
B
Fe2(SO4)3 $$\buildrel \Delta \over \longrightarrow $$
C
S + H2SO4 $$\buildrel \Delta \over \longrightarrow $$
D
H2SO4 + PCl5 $$\buildrel \Delta \over \longrightarrow $$

Explanation

Fe2(SO4)3 $$\buildrel \Delta \over \longrightarrow $$ Fe2O3 + 3SO3

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Medical

NEET

Graduate Aptitude Test in Engineering

GATE CSE GATE ECE GATE ME GATE PI GATE EE GATE CE GATE IN