Question

The auto catalyst in the redox reaction involving acidified potassium permanganate and oxalic acid is

• A. $Mn^{2+}$
• B. $SO_4^{2-}$
• C. $CO_2$
• D. $H_2O$

Hint:

In some redox reactions, one of the products can act as a catalyst, leading to an increase in the reaction rate over time. Recognizing common autocatalytic species, like $Mn^{2+}$ in permanganate reactions, can be helpful.

Answer 1

The Correct Option is A

Step 1: Write the balanced redox reaction.
$2MnO_4^-(aq) + 5C_2O_4^{2-}(aq) + 16H^+(aq) \rightarrow 2Mn^{2+}(aq) + 10CO_2(g) + 8H_2O(l)$ Step 2: Identify the products of the reaction.
The products are $Mn^{2+}$, $CO_2$, and $H_2O$. Step 3: Understand autocatalysis.
Autocatalysis is when a product of the reaction catalyzes the reaction itself. Step 4: Determine which product acts as a catalyst.
$Mn^{2+}$ ions act as a catalyst for this reaction. The reaction is slow initially and speeds up as $Mn^{2+}$ is formed. Thus, the autocatalyst is $ \boxed{Mn^{2+}} $.