Which of the following substances will not give a brick-red precipitate with Fehling's solution?

Glyoxal $(OHC-CHO)$ on being heated with concentrated $NaOH$ forms:

Ketones react with $Mg-Hg$ followed by treatment with water to give:

Identify the reagents $X$ and $Y$ in the following reaction sequence:
$CH_3COCl \xrightarrow{X} CH_3CH_2OH$
$CH_3COCl \xrightarrow{Y} CH_3CHO$

Reduction of aldehydes and ketones to hydrocarbons takes place in the presence of:

$A$ 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?