17
MCQ (Multiple Correct Answer)
The linear shape of $\mathrm{CO}_2$ is due to ............ .
A
$s p^3$ hybridisation of carbon
B
$s p$ hybridisation of carbon
C
$p \pi-p \pi$ bonding between carbon and oxygen
D
$s p^2$ hybridisation of carbon
18
MCQ (Multiple Correct Answer)
$\mathrm{M}_3 \mathrm{SiO}$ is used during polymerisation of organo silicones because
A
chain length of organo silicone polymers can be controlled by adding $\mathrm{Me}_3 \mathrm{SiCl}$
B
$\mathrm{Me}_3 \mathrm{SiCl}$ blocks the end terminal of silicone polymer
C
$\mathrm{Me}_3 \mathrm{SiCl}$ improves the quality and yield of the polymer
D
$\mathrm{Me}_3 \mathrm{SiCl}$ acts as a catalyst during polymerisation
19
MCQ (Multiple Correct Answer)
Which of the following statements are correct ?
A
Fullerenes have dangling bonds
B
Fullerenes are cage-like molecules
C
Graphite is thermodynamically most stable allotrope of carbon
D
Graphite is slippery and hard and therefore used as a dry lubricant in machines.
20
MCQ (Multiple Correct Answer)
Which of the following statements are correct? Answer on the basis of given figure.
A
The two bridged hydrogen atoms and the two boron atoms lie in one plane
B
Out of six $\mathrm{B}-\mathrm{H}$ bonds two bonds can be described in terms of 3 centre 2 electron bonds
C
Out of six $\mathrm{B}-\mathrm{H}$ bonds four $\mathrm{B}-\mathrm{H}$ bonds can be described in terms of 3 centre 2 electron bonds
D
The four terminal $\mathrm{B}-\mathrm{H}$ bonds are two centre-two electron regular bonds
21
MCQ (Multiple Correct Answer)
Identify the correct resonance structures of carbon dioxide from the ones given below
A
$\mathrm{O}-\mathrm{C} \equiv \mathrm{O}$
B
$\mathrm{O}=\mathrm{C}=\mathrm{O}$
C
${ }^{-} \mathrm{O} \equiv \mathrm{C}-\mathrm{O}^{+}$
D
${ }^{-} \mathrm{O}-\mathrm{C} \equiv \mathrm{O}^{+}$