Identify the product of ozonolysis of $but-2-ene$ from the following:

Which of the following alkenes does not undergo anti-Markovnikov addition of $HBr$?

Assertion $(A)$: Reaction of $but-1-ene$ with $HBr$ gives $1-bromobutane$ as the major product.
Reason $(R)$: Addition of $HBr$ to unsymmetrical alkenes proceeds according to Markovnikov's rule.
The correct answer is

The major product formed in the following reaction is:

The addition reaction of $1,3$-butadiene with bromine yields ........

Identify the species $X$ in the reaction: $CH_3-CH=CH_2 + [O] \xrightarrow{\text{conc. acidic } KMnO_4} X + HCOOH$