The alkene that gives only acetone upon ozonolysis is .......

Consider the following reactions:
$Ph-CH_2-CH=CH_2 \xrightarrow{H^+/H_2O} P$
$Ph-CH_2-CH=CH_2 \xrightarrow[(ii) NaBD_4]{(i) Hg(OAc)_2, H_2O} Q$
$Ph-CH_2-CH=CH_2 \xrightarrow[(ii) H_2O_2/OH^-]{(i) BD_3, THF} R$
Identify the products $P, Q$ and $R$.

Ozonolysis of an alkene produces only one dicarbonyl compound. The structure of the alkene is:

How many products are formed in the following reaction?
$1,4$-dimethylcyclohex-$1$-ene + $HBr \rightarrow$ ?

The major product $(P)$ formed in the reaction below is: $HC \equiv C-CH_2-CH=CH_2 \xrightarrow[CCl_4, 253 \ K]{Br_2(1 \ mol)} P$

$R_f$ value for $2$-methylpropene in a solvent system (Ethyl acetate + ether) is $0.42$. $2$-methylpropene is treated with dilute $H_2SO_4$ to give major organic product $(X)$. $R_f$ value for $(X)$ in the same solvent system under identical condition will be: