Which of the following compounds gives carbon dioxide with $NaHCO_3$?

The distinguishing test between methanoic acid and ethanoic acid is

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

Consider the following compounds:
$(i) \, C_6H_5COCl$
$(ii) \, p-NO_2-C_6H_4-COCl$
$(iii) \, p-CH_3-C_6H_4-COCl$
$(iv) \, p-CHO-C_6H_4-COCl$
The correct decreasing order of their reactivity towards hydrolysis is:

$C_6H_5COCl + C_6H_5COONa \xrightarrow{\Delta} \text{ . . . . . . }$.

Given below are some statements concerning formic acid. Which of them is true?