What is the main product of the reaction between $2-methylpropene$ and $HBr$?

Identify the products obtained in the ozonolysis of propene.

The product$(s)$ in the following sequence of reactions will be: $Me-C \equiv C-Me \xrightarrow[2. \text{dil. alkaline } KMnO_4]{1. Na/NH_3(liq.), \text{ethanol}, -33^\circ C}$ Product$(s)$

When $2-$Methylbut$-2-$ene is treated with hydrogen chloride,the major product obtained is

Which of the following reagents reacts with $but-1-ene$ to give an optically inactive product?

The product of the following reaction: $CH_2=CH-CCl_3 + HBr$ is: