How many moles of $BH_3$ are needed to react completely with $2 \ mol$ of $1$-pentene in a hydroboration-oxidation reaction?

What is the major product of the following reaction?
Cyclopentene + $D_2$ $\xrightarrow{Pd}$ ?

Arrange the following alkenes in decreasing order of stability. Choose the correct answer from the options given below:

An alkene $'A'$ contains three $C-C$,eight $C-H$ $\sigma$ bonds and one $C-C$ $\pi$ bond. $'A'$ on ozonolysis gives two moles of an aldehyde of molar mass $44 \ u$. Write the $IUPAC$ name of $'A'$.

Reagent $(A)$ in the reaction is

Alkenes react with water in the presence of acid as a catalyst to form alcohols: $CH_3-CH=CH_2 + H_2O \xrightarrow{H^{+}} CH_3-CH(OH)-CH_3$. The reaction takes place in accordance with: