Hydrogen sulphide, potassium permanganate, và sulfuric acid (H2S KMn
O4 H2SO4) are available in almost all chemical labs across the World. In the H2SO4 medium, KMn
O4 and H2S react mainly. The reaction is a Redox reaction.

Bạn đang xem: When h2s is passed through acidified kmno4 we get:

O4 H2SO4

The chemical compound with the chemical formula H2S is Hydrogen sulfide. It is a colorless gas with rotten eggs ‘ distinctive foul smell. Besides it is very poisonous as well as corrosive and flammable also.

Potassium permanganate is a compound & medication of inorganic chemical substances. It is a strong oxidizing agent. KMn
O4 is a salt consisting of K+ and Mn
O4 -1 ion and has the chemical formula KMn
O4. To offer intensely pink or purple alternatives, it dissolves in water. In Solid-state it forms prismatic purplish-black glistening crystals.

Sulphuric acid is indeed a mineral acid having a molecular formula H2SO4 It is a colorless, odorless, and syrupy liquid that is soluble in water. In this reaction, it acts as an acidic medium only.

Hydrogen sulphide reacts with potassium permanganate and sulfuric acid

Hydrogen sulphide reacts with potassium permanganate and sulfuric acid khổng lồ produce Sulfer, Manganese Sulfate, potassium sulfate as well as water.

O4 + H2S + H2SO4 = S + + K2SO4 + Mn
SO4 + H2O

Now by using the ion-electron method we can balance the Oxidation-Reduction reaction.


Ion-Electron method

Ion-electron method is a very effective method khổng lồ balance equations of the Redox reactions. As the above reaction is a redox reaction, we can use the ion-electron method khổng lồ balance the reaction equation. Let’s try-

The skeleton reaction for the redox reaction is-

O4 + H2S + H2SO4 = S + + K2SO4 + Mn
SO4 + H2O

Here,The Oxidizing agent: KMn
O4 or Mn
The Reducing agent: H2S or, S-2

Reduction Half Reaction:

⇒ Mn
O4 -1 +5e + 8H+  = Mn2- + 4H2O … …. …. …. (1)

Oxidation Half Reaction:

⇒ S-2 – 2e– = S … … … … (2)


equation (1)x2 + (2)x5,

O4-1 +10e– + 16H+  = 2Mn2- + 8H2O

5S-2 – 10e– = 5S

⇒ 2Mn
O4 -1 + 5 S-2 + 16H+ = 2Mn2- + 8H2O +5S

⇒ adding necessary ions and radicals we get,

⇒ 2KMn
O4 + 5H2S + 3H2SO4 = 5S + K2SO4 + 2Mn
SO4 + 8H2O


O4 + 5H2S + 3H2SO4 = 5S +K2SO4 + 2Mn
SO4 + 8H2O

Click to readily understand ion-electron balancing redox reaction

O4 + H2O2 + H2SO4 = O2 + Mn
SO4 + K2SO4 + H2O

SO4 + KMn
O4 + H2SO4 = Fe2(SO4)3 + Mn
SO4 + H2O + K2SO4

Cl + KMn
O4 + H2SO4 = Cl2 + Mn
SO4 + Na2SO4 + K2SO4 + H2O

K2Cr2O7 + Fe
SO4 + H2SO4 = Cr2(SO4)3 + Fe2(SO4)3 + K2SO4 + H2O

Previous article
Next article
2 Comments Posted
October 27, 2020 at 11:58

Greetings from Florida! I’m bored to death at work so I decided tocheck out your website on my iphone during lunch break.

I love the info you provide here and can’t wait lớn take a look when Iget home. I’m surprised at how fast your blog loaded on my thiết bị di động ..I’m not even using WIFI, just 3G .. Anyways, superb blog!

Potassium permanganate (KMn
O4) reacts with hydrogen sulfide (H2S) and give manganese sulfate (Mn
SO4), sulfur, water and potassium sulfate. Manganese atom in KMn
O4 is reduced to lớn manganese +2 ion and sulfur atom in H2S is oxidized khổng lồ sulfur. Purple colour of KMn
O4 is reduced to colourless or pale pink colour during the reaction.

Balanced reaction of potassium permanganate and sulfur dioxide reaction is given below.

O4(aq) + 5H2S(g) + 3H2SO4(aq) → 2Mn
SO4(aq) + 5S + 8H2O(l) + K2SO4(aq)


Manganese in potassium permanganate is reduced from +7 oxidation state to lớn +2 oxidation state (Mn2+). As well, sulfur in hydrogen sulfide is oxidized from -2 oxidation state to lớn 0 oxidation state (S).

Xem thêm: Top 10 bộ phim hoạt hình khủng long (dinosaur) hay dành cho bé

Because oxidation numbers of several elements in reactants are changed when products are given, this reaction is considered as a redox reaction.

Reaction medium should be slightly acidified by adding few drops of sulfuric acid.

Physical observations during the reaction of potassium permanganate & sulfur dioxide

Dilute aqueous potassium permanganate solution is a purple colour solution. When colourless hydrogen sulfide gas is sent lớn that solution, purple colour of aqueous solution is decreased & become colourless or pale pink colour solution due lớn formation of Mn2+ cations. Also, you can see white - yellow colour precipitate (sulfur) is formed in the solution. Due to that sulfur particles, solution becomes unclear.

Safety during the reaction

Hydrogen sulfide is a highly toxic gas và acidic gas. Therefore, be careful to lớn prevent any leakages during the treating hydrogen sulfide gas in to the potassium permanganate solution.

How to lớn balance KMn
O4 và SO2 reaction

Identify oxidation number difference of elements

Because oxidation number of sulfur and manganese atoms are changed, identify what is the difference of oxidation numbers relevant lớn oxidation & reduction as below.


Exchange difference of oxidation numbers

Oxidation number difference of manganese atom is 5 & sulfur atom is 2. Then, exchange oxidation number difference as bellow.


Balancing number of oxygen atoms

Count the total number of oxygen atoms in the left side and right side separately. To lớn balance the number oxygen atoms, showroom 8 H2O molecules lớn the right side od the reaction.


Balancing number of hydrogen atoms

Count the total number of hydrogen atoms in the left side and right side separately. To lớn balance number hydrogen atoms, add 4 H+ ions khổng lồ the right side.


Now, we have obtained the balanced ionic equation of KMn
O4 & H2S reaction.

Balancing chemical equation

Now, we can balance the ionic equation and find chemically balanced equation.


Ask Your Chemistry Questions
Related Tutorials
O4 & SO2 reaction Find oxidation number of manganese atom in KMn
O4 Identify chromium cations & compounds Testing sulfate ion Testing carbonate ion Phosphate ion testing Tests for chloride ions Tests for sulfide ions

Related tutorials lớn KMn

O4 và SO2 reaction KMn
O4 and HCl reaction oxidation number of Mn atom in KMn
O4 KMnia & H2S rwaction

Related tutorials khổng lồ hydrochloric acid (HCl)

CO3 và HCl reaction p
H of HCl solution Sodium carbonate & hydrochloric acid reaction Lewis structure of HCl molecule Na
OH & HCl reaction
report this ad

Advanced Level