Transition and InnerTransition Elements - Result Question 14
####15. Sodium salt of an organic acid ’ $X$ ’ produces effervescence with conc. $H _2 SO _4$. ’ $X$ ’ reacts with the acidified aqueous $CaCl _2$ solution to give a white precipitate which decolourises acidic solution of $KMnO _4 \cdot$ ’ $X$ ’ is (2017 Main)
(a) $C _6 H _5 COONa$
(b) $HCOONa$
(c) $CH _3 COONa$
(d) $Na _2 C _2 O _4$
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Solution:
- The reaction takes place as follows
$$ \begin{aligned} & \underset{(X)}{Na _2 C _2 O _4}+\underset{\text { (Conc.) }}{H _2 SO _4} \longrightarrow Na _2 SO _4+H _2 O \underset{\text { Effervescence }}{+CO \uparrow}+CO _2 \uparrow \ & Na _2 C _2 O _4+CaCl _2 \longrightarrow CaC _2 O _4+2 NaCl \ & 5 CaC _2 O _4+2 KMnO _4+8 H _2 SO _4 \longrightarrow K _2 SO _4+5 CaSO _4 \ & \text { Purple } \ & +2 MnSO _4+10 CO _2+8 H _2 O \ & \text { Colourless } \end{aligned} $$
