Question 5 :
Which of the following phrases are not correctly associated with $S_{N^{1}}$ reaction ?<br>(1) Rearrangement is possible<br>(2) Rate is affected by polarity of solvent<br>(3) The strength of the nucleophile is important in determining rate<br>(4) The reactivity series is tertiary &gt; secondary &gt; primary<br>(5) Proceeds with complete inversion of configuration

Question 8 :
The first organic compound synthesised in the laboratory from its elements.

Question 10 :
Linear combination of two hybridised orbitals&#160;belonging to two atoms and each having one&#160;electron leads to the formation of:

Question 17 :
The conversion of $ - \operatorname { coch } _ { 2 } - t o - C H _ { 2 } - C H _ { 2 } - $ using Hg/ Zn and HCI is known as

Question 20 :
Assertion: The bond angle of $PBr_{3}$ is greater than that of $PH_{3}$, but bond angle of $NBr_{3}$ is less than that of $NH_{3}$. Reason: Electronegativity of phosphorus atom is less than that of nitrogen.

Question 21 :
The $M-O-M$ bond angles in ${M}_{2}O$ (where $M$ is halogen) is in the order: