Which of the reagent is used to convert $2-Butanone$ into propanoic acid?

$A$ carbonyl compound $X$ $(C_3H_6O)$ on oxidation gives a carboxylic acid $Y$ $(C_3H_6O_2)$. The oxime of $X$ is:

Which of the following reagents must be used in the given interconversion? The reaction involves the reduction of $4$-hydroxycyclohexanone to cyclohexanol,where the carbonyl group is reduced to a methylene group while the hydroxyl group remains unaffected.

Which of the following undergoes haloform reaction?
$ (i) \ CH_3CH_2COCH_2Cl $
$ (ii) \ C_6H_5COCH_3 $
$ (iii) \ C_6H_5COCHCl_2 $
$ (iv) \ CH_3CH_2COCCl_3 $

Which of the following compounds will give a positive test with Tollen's reagent?

Which of the following is an example of a conjugated diketone?