The eclipsed and staggered conformation of ethane is due to -

In the given compounds how many are unsaturated hydrocarbon?

How many ${\mathrm{sp}}^2-{\mathrm{sp}}^2$ bonds found in the given compound.

What is the final product of the given reaction?

${\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{CH}\stackrel{\mathrm{Na}}{\to }\stackrel{{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{I}}{\to }\mathrm{Product}$

Select the correct reactivity order of dehydrohelogenation reaction for the following halides with alcoholic $\mathrm{KOH}.$

(i) ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2-\mathrm{Br}$

(ii) ${\mathrm{CH}}_3-\mathrm{CH}\left(\mathrm{Br}\right)-\mathrm{CH}{\left({\mathrm{CH}}_3\right)}_2$

(iii) ${\mathrm{CH}}_3-\mathrm{CH}\left(\mathrm{Br}\right)-{\mathrm{CH}}_2\mathrm{Ph}$