The major product of the following reaction is:

What is the major product obtained when $1$-butanol is heated with concentrated $H_2SO_4$?

Write the products of the addition reaction $ >C = C < + XY \to $

The order of increasing reactivity towards $HCl$ of the following compounds will be:
$(1)$ $CH_2 = CH_2$
$(2)$ $(CH_3)_2C = CH_2$
$(3)$ $CH_3CH = CHCH_3$

Ethylene reacts with $Br_2$ to give $1, 2$-dibromoethane. Which intermediate is formed that leads to anti-addition?

Amongst the following,the major product of the given chemical reaction is $.....$ .