Most probable predictions:
Titration: KMnO4 - Mohr salt (Your titre value must be around 23)
Organic compounds: Formaldehyde and Glycerol
Inorganic salt: Magnesium Sulphate (MgSO4)
Most students from different schools were questioned the same in their second prelims. Many claim to have been already confirmed these compounds by their chemistry teacher. You may prepare the above very well, but I do not recommend to skip the rest. Take decisions at your own risk.
Lastly, all the best! :D