(a) Write the main product formed when propanal reacts with the following reagents :
(i) 2 moles of in presence of dry
(ii) Dilute
(iii) followed by heating with
in ethylene glycol
(b) Arrange the following compounds in increasing order of their property as indicated :
(i) — acid character
(ii) Acetone, Acetaldehyde, Benzaldehyde, Acetophenone — reactivity towards the addition of .