The reaction shown in the image is called:

Which of the following carbonyl compounds gives both Fehling's test and iodoform test?

$A$ carbonyl compound $X$ $(C_8H_8O)$ undergoes disproportionation with conc. $KOH$ on heating. The product of $X$ with $Zn-Hg/HCl$ is $Y$ and the product of $X$ with $NaBH_4$ is $Z$. What are $Y$ and $Z$ respectively?

Identify the product $A$ in the following reaction:
$\text{Substrate} \xrightarrow{MnO_2} A$
(The substrate is a benzene ring with a $-OH$ group,a $-COOH$ group,and a $-CH(CH_2CH_3)CHO$ group attached to it.)

Arrange the following compounds in the increasing order of their reactivity towards the nucleophilic addition of $HCN$:
$1. HCHO$
$2. CH_3COCH_3$
$3. PhCOCH_3$
$4. PhCOPh$

In the given reaction :
$CH_3CHO$ $\xrightarrow[(i) \ NaCN/HCl]{(ii) \ H_2O/H^{\oplus}/\Delta} (A)$ $\xrightarrow[reagent]{Fenton} (B)$
$(B)$ will be :