Redox Reactions

In a chemical reaction when electrons transfer simultaneously between substances, it is called as the redox reaction.  In redox reaction, one substance gets oxidized by losing electrons and another substance reduces by gaining the electrons. These two processes together occurs in a redox reaction.

Kindly go through the solution 

$5C_2{O}_4^{2-}+2Mn{O}_4^{-}+16H^{+}\to 2M{n}^{+}+8H_{2}O+10C{O}_2$

5 moles of $C_2{O}_4^{2-}$ ${}_{}{}_{}^{}$ is needed to reduce 2 moles of $Mn{O}_4^{2-}$ ${}_{}^{}$

1 mole of $C_2{O}_4^{2-}$  is needed to reduce $\frac{2}{5}$  moles of $Mn{O}_4^{2-}$

H2SO5

: x + 2 (+1) + 3 (–2) + 2 (–1) = 0

x = + 6.

Mass of Na⁺ in 50 ml = 70 * 50 = 3500 mg

23000 mg of Na⁺ is present in 85000 mg of NaNO₃ (1 mole NaNO₃ contains 1 mole Na⁺)

$\therefore 3500$   mg Na⁺ will be present in   $\frac{85000}{23000}*3500$

= 12934.78 mg

= 12.93478 gm

$\cong 13$          

In an oxidation-reduction reaction or redox reaction, the process of oxidation (addition of electrons) and reduction (removal of electrons) happens at the same time.

Redox reaction does not have a fixed formula but is an equation that forms when oxidation and reduction occur simultaneously. For example, 2Fe + 3Cl? 2FeCl? (Fe loses electrons and Cl gains).

Redox reactions are of four kinds: Decomposition, Combination, Displacement, and disproportionation reactions.

$Mn{O}_2+4HCl\to MnC{l}_2+C{l}_2+2H_{2}O$

$\begin{array}{l}C{l}_2+2Kl\to 2KCl+I_2\\ I_2+2N{a}_2{S}_2{O}_3\to 2Nal+N{a}_2{S}_4{O}_6\end{array}$

Here, meq of MnO₂ = meq of Na₂S₄O₆

$\frac{w}{E}*1000=M*n-factor*V$

$\frac{w}{87/2}*1000=0.1*1*60$

Mass of MnO₂ in sample = 0.261 g

Percentage of MnO₂ in sample = $\frac{0.261}{2}*100$  

 = 13.05%