The major product formed in the following reaction is :

Propanal and pentan-$3$-one are the ozonolysis products of an alkene. What is the structural formula of the alkene?

Alkenes react with water in the presence of acid to form alcohols. Identify the steps involved in the mechanism of the reaction from the following :
a) Nucleophilic addition of hydroxide ion to alkene
b) Protonation of alkene by electrophilic attack of $H_3O^{+}$
c) Electrophilic attack of $H_2O$ on carbanion
d) Nucleophilic attack of $H_2O$ on carbocation
e) Loss of $^{\ominus}OH$ to form an alcohol
f) Loss of $H^{\oplus}$ to form an alcohol

$X$ in the above reaction is

The addition of $HI$ to the double bond of propene gives isopropyl iodide as the major product because the addition proceeds through:

For the synthesis of $but-1-ene$,$CH_3MgI$ should be treated with: