Q.
$\underset{\text{Black}}{X ( S )} \xrightarrow{\text { dil } HCl } Y \uparrow \xrightarrow [NaOH]{Na_2[Fe(CN)_5(NO)]}$
Purple solution gas $Y$ has been allowed to react with following species in neutral/acidic medium:
(a) $FeCl _{3}$
(b) $CuSO _{4}$
(c) $BaCl _{2}$
(d) $SO _{2}$
(e) $Cr _{2} O _{7}^{2-}$
(f) $CH _{3} COONa$
(g) $Hg _{2}^{2+}$
Then calculate value of $(P+Q-R)$
$P$ : Number of species which undergoes redox reaction with gas $Y$.
$Q$ : Number of species with which gas $Y$ undergoes precipitation.
$R$ : Number of species with which gas $Y$ produce no observable change.
Organic Chemistry – Some Basic Principles and Techniques
Solution: