Benzaldehyde and acetaldehyde can be differentiated by

What is $X$ in the following reaction?
$2 CH_3COCH_3 \stackrel{Ba(OH)_2}{\longrightarrow} X$

Which of the following compounds will not undergo the Cannizzaro reaction when treated with $50\%$ aqueous alkali?

$C_7H_6O$ is the molecular formula of $X$,which gives a negative Fehling test but a positive Tollen's test. $X$ $\xrightarrow[AcONa]{Ac_2O} Y$ $\xrightarrow[Me_2NH]{1. SOCl_2} Z$. The correct option is:

Arrange the following compounds in order of decreasing reactivity for nucleophilic addition reaction:
$(I)$ $CH_3COCH_2Cl$
$(II)$ $ClCH_2CHO$
$(III)$ $HCHO$
$(IV)$ $CH_3COCH_3$

Which of the following gives a positive iodoform test?