How to Calculate Molar Mass and Understand Potassium Iodate’s Reactions
Potassium iodate is an ionic chemical compound that consists of K+ ions and IO3- ions in a 1:1 ratio. It is an oxidizing agent, and as a result, it can cause fires if in contact with combustible materials or reducing agents. Few uses of potassium iodate: it is a chemical compound which is used for the iodization of common edible salts. It provides a convenient way of performing iodometric work. In many countries, potassium iodate is used as a source for dietary iodine. It is also one ingredient in some baby formula milk. Just like, potassium bromate, potassium iodate is occasionally used as a maturing agent in baking.
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What Is KIO3 In Chemistry?
The chemical formula for potassium iodate is KIO3. It can be prepared by reacting potassium base with iodic acid or by reacting potassium hydroxide to iodine. The second reaction produces both iodide and iodate. It is used as an analytical reagent. Potassium chlorate and potassium bromate are some other ions. Sodium iodate is another cation. Soluble in water at 4.74 g/100 ml(0°c); 9.16 g/100 ml(25°c); 32.3 g/100 ml(100°c). KIO3 is soluble in kl solution. KIO3 is insoluble in alcohol, liquid ammonia, and nitric acid. The atomic mass of potassium in KIO3 is 39.0983; iodine is 126.90447, and oxygen is 15.9993. Melting point at 560°c(1,040°F; 833 K)(decomposes). Whenever it's heated to decomposition, it always emits very toxic fumes. KIO3 has got good stability and is approved as an iodine supplement. Iodine is essential for good health and is needed for effective thyroid gland operation, which affects the body's metabolic and immunity functions. The exposure to radiation specifies as a 'thyroid blocking agent' to prevent uptake of radioactive iodine. Some potassium iodate is used as a food additive. For example, iodine can be added to salt in the form of potassium iodide or potassium iodate. KIO3 has higher stability in the presence of salt impurities, humidity, and porous packaging.
The Molar Mass Of Potassium Iodide
The molar mass of potassium iodide is 214.001 g/mol. KIO3 chemical name is potassium iodate iodic acid potassium salt.
Physical Properties Of Potassium Iodate
The physical properties of potassium iodate are:
1. It does not have any odor. Simply, odorless.
2. It sometimes appears as colorless crystals or white crystalline powder.
3. It has two covalently-bonded units.
4. It is capable of holding heat till 313 J Kg-1 K-1.
5. Melts at 560°C, along with partial decomposition, by releasing oxygen.
6. Its density is 3.90 g/cm3.
7. It is stable at ordinary temperatures. Materials to avoid included organics, combustibles, phosphorus, sulfur, carbon, powdered metals, cyanides, hydrides, reliable reducing agents, aluminum, and peroxides. Explosive when mixed with combustible material.
8. It accepts three hydrogen bonds(we can call it a hydrogen bond acceptor)
9. It is soluble in Kl solution.
10. It is moderately soluble in cold water; 4.74 g/100ml at 0°C.
11. It has a higher solubility in boiling water 32.3 g/100ml at 100°C.
12. It is insoluble in alcohol and nitric acid.
13. It has five heavy atoms.
14. Complexity is 49.8.
15. The compound is canonicalized.
Now, we will be learning about chemical properties of potassium iodate.
Chemical Properties Of Potassium Iodate
Just like we learned about the Physical properties of potassium iodate previously, chemical properties of potassium iodate are explained below:
When in the presence of strong acid like sulphuric acid, potassium iodate combines with potassium iodide, it produces potassium sulfate, iodine, and water.
KIO3 + 5Kl + 3H2SO4 → 3K2SO4 + 3H2O + 3l2
As we know, when potassium iodide is titrated with chlorine water in a neutral solution, the reaction which takes place is expressed by the equation:
Kl + 3Cl2 + 3H2O → KCl + HIO2 + 5HCl
While on the other hand, it may not be so well known that if a large excess of free hydrochloric acid is present during the titration, chloroform or carbon tetrachloride being used as before for an indicator, the reaction will be
Kl + Cl2 → KCl + ICl
In both cases, the end of the reaction is shown by the immiscible solvent becoming colorless.
If instead of chlorine water, we titrate with a solution of potassium iodate, the stage at which the reaction stops is likewise dependent upon the concentration of the acid.
Potassium iodate, when reacted with silver nitrate, produces silver iodate and potassium nitrate. The chemical reaction is as given below:
KlO3 + AgNO3 → AgIO3 + KNO3
Solved Examples
Question 1: How to make a potassium iodide solution?
Answer: Mix 5g of potassium iodide in 10ml of water. Mix the two solutions and add water to make 100ml—Mix 2g in 10ml in water. To 10ml of the resolution, add 90ml of water and 20g of sodium bisulfite.
Question 2: What happens when potassium iodide gets added to lead nitrate?
Answer: when we add potassium iodide to lead nitrate, those particles combine and produce two new compounds, a yellow solid named lead iodide and a white solid named potassium nitrate. Yellow cloud formation indicates that the chemical changes have taken place.
Fun Facts
Potassium iodide is used in treating victims of nuclear accidents, as it blocks the thyroid gland’s uptake of radioactive iodine. It is also possible for radioactive iodine to get into the food and water and contaminate people in that way. Table salts also contain iodine, but not too much to provide any protection to your thyroid in a nuclear emergency.
FAQs on Potassium Iodate: Key Properties, Structure, and Uses
1. What is potassium iodate, and what is its chemical formula?
Potassium iodate is an inorganic ionic salt with the chemical formula KIO₃. It is composed of a potassium cation (K⁺) and an iodate anion (IO₃⁻). It is a white, crystalline, odourless solid that is known for being a strong oxidizing agent. Its molar mass is approximately 214 g/mol.
2. What are the key physical and chemical properties of potassium iodate?
Potassium iodate exhibits several distinct properties that are important for its applications. Key properties include:
- Appearance: It is a white crystalline powder or solid.
- Solubility: It is soluble in water, but its solubility is lower than that of potassium iodide. It is practically insoluble in alcohol.
- Oxidizing Nature: As a strong oxidizing agent, it can react vigorously with reducing agents and combustible materials.
- Stability: It is more stable than potassium iodide, especially in the presence of moisture and air, which is why it is often preferred for the iodization of salt.
- Melting Point: It has a high melting point of 560 °C (1,040 °F), at which it starts to decompose.
3. What are the main uses and applications of potassium iodate?
Potassium iodate has several important applications across different fields:
- Food Fortification: It is commonly used to iodize table salt to prevent iodine deficiency disorders like goitre. Its stability makes it superior to potassium iodide for this purpose.
- Analytical Chemistry: It serves as a primary standard in redox titrations, particularly in a process called iodometry, to standardize solutions of sodium thiosulfate.
- Medical Use: In a nuclear emergency, potassium iodate tablets can be administered to block the thyroid gland's uptake of harmful radioactive iodine.
- Baking Industry: It can be used as a maturing agent and a dough conditioner in bread making.
4. What is the molecular structure of the iodate ion (IO₃⁻)?
The structure of the iodate ion (IO₃⁻) can be determined using the VSEPR (Valence Shell Electron Pair Repulsion) theory. The central iodine atom is bonded to three oxygen atoms and has one lone pair of electrons. This arrangement of three bond pairs and one lone pair results in a trigonal pyramidal geometry, similar to the structure of ammonia (NH₃). The presence of the lone pair repels the bonding pairs, giving the ion its characteristic shape.
5. How is potassium iodate (KIO₃) different from potassium iodide (KI)?
While both are sources of iodine, potassium iodate (KIO₃) and potassium iodide (KI) are chemically distinct. The primary difference lies in the oxidation state of iodine and their resulting chemical behaviour. In KIO₃, iodine is in the +5 oxidation state (as part of the iodate ion, IO₃⁻), making it a strong oxidizing agent. In KI, iodine is in the -1 oxidation state (as the iodide ion, I⁻), making it a reducing agent. This also explains why KIO₃ is more stable and less prone to oxidation by air, making it a better choice for long-term applications like salt iodization.
6. How is potassium iodate used as a primary standard in titrations?
Potassium iodate is an excellent primary standard because it is highly pure, stable, non-hygroscopic (does not absorb moisture from the air), and has a high molar mass. In a typical iodometric titration, a precisely weighed amount of KIO₃ is reacted with an excess of potassium iodide (KI) in an acidic solution. This reaction liberates a precise and known amount of iodine (I₂). This liberated iodine is then titrated with a sodium thiosulfate (Na₂S₂O₃) solution, allowing for the exact concentration of the thiosulfate solution to be determined.
7. Why is the equivalent weight of potassium iodate one-sixth of its molecular weight in certain redox titrations?
The equivalent weight of a substance in a redox reaction is its molecular weight divided by the n-factor (the number of electrons gained or lost per molecule). In acidic medium, the iodate ion (IO₃⁻) acts as an oxidizing agent and is ultimately reduced to the iodide ion (I⁻). The half-reaction is:
IO₃⁻ + 6H⁺ + 6e⁻ → I⁻ + 3H₂O
In this reaction, the oxidation state of iodine changes from +5 in IO₃⁻ to -1 in I⁻. The total change in oxidation state is (+5) - (-1) = 6. Therefore, one mole of KIO₃ gains 6 moles of electrons. The n-factor is 6, and its equivalent weight is calculated as (Molecular Weight / 6).
8. Are there any safety precautions to consider when handling potassium iodate?
Yes, safety precautions are necessary when handling potassium iodate due to its chemical properties. As a strong oxidizing agent, it must be stored away from flammable materials, organic compounds, and reducing agents to prevent the risk of fire or explosion. It can also be an irritant to the eyes, skin, and respiratory system. Therefore, it is important to use appropriate personal protective equipment (PPE), such as gloves and safety glasses, and to work in a well-ventilated area when handling it in a laboratory setting.
