Chemistry 2nd Paper MCQ-Sylhet Board-2023

1. $\mathrm{R}-\mathrm{NH}_{2}+\mathrm{CHCl}_{3}+\mathrm{KOH}$ (alc. $) \xrightarrow{\Delta} \mathrm{X}+\mathrm{KCl}+\mathrm{H}_{2} \mathrm{O}$

In the reaction-

i. compound X is offensive smelling

ii. primary amine is detected

iii. approve the presence of chloroform

Which one is correct?

2. What is the value of $\mathrm{R}$ in S.I. unit?

3. What is the ppm concentration of 0.025 $\mathrm{M} \mathrm{Na}_{2} \mathrm{CO}_{3}$ solution?

4. Which one reduces the activity of benzene ring?

5. Which one is produced by Williamson reaction?