POTASSIUM PERMANGANATE FORMULA
Potassium permanganate (KMnO4) is a chemical compound consisting of potassium (K+) and permanganate (MnO4-) ions. It is a dark purple crystalline solid that dissolves readily in water to form a vibrant purple solution. Potassium permanganate is widely used in various applications, including water treatment, disinfection, laboratory experiments, and medical treatments.
Chemical Equation: The chemical equation for the reaction of potassium permanganate in water can be represented as follows:
2KMnO4 + 3H2O → 2KOH + 2MnO2 + 5O2
Explanation: Potassium permanganate is a powerful oxidizing agent, meaning it has the ability to accept electrons from other substances during a chemical reaction. When dissolved in water, potassium permanganate dissociates into potassium ions (K+) and permanganate ions (MnO4-).
The permanganate ion (MnO4-) is the active species responsible for its oxidizing properties. It readily donates oxygen atoms to other substances, resulting in the reduction of the permanganate ion to manganese dioxide (MnO2). This reaction produces oxygen gas (O2) as a byproduct.
Uses of Potassium Permanganate:
Potassium permanganate is commonly used in water treatment processes to remove impurities and odors. It reacts with organic and inorganic compounds, oxidizing them and breaking them down into simpler, less harmful substances.
In the medical field, potassium permanganate is used for wound disinfection and as an antiseptic. It has strong oxidizing properties that can help kill bacteria, fungi, and other microorganisms. However, it should be used with caution and under proper medical guidance, as it can cause skin irritation and staining.
In laboratory experiments, potassium permanganate is used as a reagent for various chemical reactions, including redox titrations, organic synthesis, and qualitative analysis.
It’s important to note that potassium permanganate is a strong oxidizer and should be handled with care. It can cause skin and eye irritation, and prolonged exposure or ingestion can be harmful. Proper protective measures, such as wearing gloves and goggles, should be taken when working with potassium permanganate.
Solved Examples on Potassium permanganate formula:
Example 1: Calculation of Molar Mass Calculate the molar mass of potassium permanganate (KMnO4).
The molar mass of potassium is 39.10 g/mol, the molar mass of manganese is 54.94 g/mol, and the molar mass of oxygen is 16.00 g/mol.
To calculate the molar mass of potassium permanganate (KMnO4), we add the molar masses of potassium, manganese, and oxygen.
Molar Mass = (Number of potassium atoms × Molar mass of potassium) + (Number of manganese atoms × Molar mass of manganese) + (Number of oxygen atoms × Molar mass of oxygen)
Molar Mass = (1 × 39.10 g/mol) + (1 × 54.94 g/mol) + (4 × 16.00 g/mol)
Molar Mass = 39.10 g/mol + 54.94 g/mol + 64.00 g/mol
Molar Mass = 158.04 g/mol
Therefore, the molar mass of potassium permanganate (KMnO4) is 158.04 g/mol.
Example 2: Redox Reaction Potassium permanganate (KMnO4) is commonly used as an oxidizing agent. In a redox reaction, it reacts with hydrogen peroxide (H2O2) to produce oxygen gas (O2) and water (H2O). If you mix 10 mL of a 0.1 M potassium permanganate solution with 20 mL of a 0.2 M hydrogen peroxide solution, what is the limiting reagent and the number of moles of the excess reagent?
The balanced chemical equation for the redox reaction is:
2KMnO4 + 3H2O2 → 2MnO2 + 2KOH + 3O2 + 2H2O
According to the stoichiometry of the balanced equation, 2 moles of potassium permanganate react with 3 moles of hydrogen peroxide.
To determine the limiting reagent, we compare the number of moles of each reagent used:
Moles of KMnO4 = (Concentration of KMnO4 × Volume of KMnO4)
= (0.1 M × 0.01 L) = 0.001 moles
Moles of H2O2 = (Concentration of H2O2 × Volume of H2O2)
= (0.2 M × 0.02 L) = 0.004 moles
Since the ratio of moles of KMnO4 to moles of H2O2 is 2:3, we can see that the moles of H2O2 are limiting. Therefore, hydrogen peroxide is the limiting reagent.
To calculate the number of moles of the excess reagent (KMnO4), we subtract the moles of the limiting reagent from the total moles:
Moles of excess KMnO4 = (Moles of KMnO4 – Moles of H2O2)
= (0.001 moles – 0.004 moles)
= -0.003 moles
Since the result is negative, it means that there is no excess KMnO4.
Therefore, in the given reaction, hydrogen peroxide is the limiting reagent, and there are no excess moles of potassium permanganate.
Frequently asked Questions on Potassium permanganate formula:
- What is the purpose of using potassium permanganate?
Potassium permanganate has various applications, including water treatment, disinfection, laboratory experiments, and medical treatments. It is commonly used as an oxidizing agent to remove impurities, kill microorganisms, and facilitate chemical reactions.
- How is potassium permanganate used in water treatment?
Potassium permanganate is used in water treatment to remove impurities, such as organic compounds, iron, and hydrogen sulfide. It acts as an oxidizing agent, reacting with these substances and breaking them down into simpler and less harmful forms.
- Can potassium permanganate be used for wound disinfection?
Yes, potassium permanganate can be used for wound disinfection. It has strong oxidizing properties that can help kill bacteria, fungi, and other microorganisms. However, it should be used under proper medical guidance and diluted to an appropriate concentration.
- Does potassium permanganate stain the skin?
Yes, potassium permanganate can stain the skin, leaving a brownish or purplish color. This staining is temporary and can be removed with the application of dilute acid, such as lemon juice or vinegar, followed by thorough washing with soap and water.
- Is potassium permanganate toxic?
Potassium permanganate is generally considered to be low in toxicity. However, it can cause skin and eye irritation. Ingestion or inhalation of large amounts can be harmful. It is important to handle potassium permanganate with care and follow proper safety guidelines.
- Can potassium permanganate be used to treat fish diseases in aquariums?
Yes, potassium permanganate is sometimes used to treat certain fish diseases, such as external parasites or fungal infections, in aquariums. However, it should be used cautiously and in the correct dosage, as it can be harmful to fish and other aquatic organisms if not used properly.
- How should potassium permanganate be stored?
Potassium permanganate should be stored in a cool, dry place, away from flammable substances and sources of heat. It should be kept in a tightly sealed container to prevent moisture absorption and degradation. It is also important to store it out of reach of children and pets.
