Concentrated nitric acid oxidises cane sugar to

Identify the product $B$ in the following series of reaction.
$CH_3COOH + CH_3CH_2OH \rightleftharpoons{H^{+}} CH_3COOCH_2CH_3{_{\text{(A)}}} \xrightarrow[Ni/Pd, \Delta]{H_2} CH_3CH_2OH + CH_3CH_2OH{_{\text{(B)}}}$

Arrange the following compounds in order of their increasing acid strength:
$I: HO_2C(CH_2)_4CO_2H$
$II: CH_3CH(COOH)_2$
$III: HOOC-COOH$
$IV: HO_2C(CH_2)_3CO_2H$

The product $(D)$ in the following reaction sequence is: $HOCH_2CH_2CH_2COOCH_2CH_3$ $\xrightarrow{PCC} (A)$ $\xrightarrow[{(1 \ molar \ equivalent)}]{H_2C=CHMgBr} (B)$ $\xrightarrow{NH_4Cl/H_2O} (C)$ $\xrightarrow[H_2O]{KOH}$ $\xrightarrow{H_3O^{+}}$ $\xrightarrow[pyridine]{(CH_3CO)_2O} (D)$

What is the product of the reaction between lactic acid and dilute $H_2SO_4$?

Which one of the following compounds forms a red coloured solution on treatment with neutral $FeCl_3$ solution?