Ionic Compounds Chemistry: Polyatomic Ions Quiz

The chemical formula CO₃²⁻ corresponds to the carbonate ion. Carbonate is a polyatomic ion composed of one carbon atom bonded to three oxygen atoms, carrying a charge of -2. It is a versatile ion found in various compounds, including common substances like calcium carbonate, which is a key component of limestone and chalk.

Cyanide is a highly toxic polyatomic ion formed by a carbon atom triple-bonded to a nitrogen atom. Despite its toxicity, cyanide is utilized in several industrial processes, including gold mining, where it helps in extracting gold from ores, and in electroplating, where it is used for depositing metals onto surfaces. The danger associated with cyanide stems from its ability to inhibit cellular respiration by binding to cytochrome c oxidase in mitochondria, preventing oxygen utilization.

CrO42- is a polyatomic ion composed of one chromium atom and four oxygen atoms. The name of this ion is chromate. The other options are incorrect as they represent different polyatomic ions: phosphate (PO43-), carbonate (CO32-), sulfite (SO32-), and sulfate (SO42-).

OH- is the chemical formula for the hydroxide ion. It consists of one oxygen atom bonded to one hydrogen atom and carries a negative charge. The hydroxide ion is commonly found in bases and plays a crucial role in many chemical reactions. Therefore, the correct description for OH- is hydroxide.

NO₃⁻ is the chemical formula for nitrate. Nitrate is an ion that consists of one nitrogen atom bonded to three oxygen atoms. It has a -1 charge, which is indicated by the negative sign. Nitrite, on the other hand, has the chemical formula NO₂⁻ and consists of one nitrogen atom bonded to two oxygen atoms. Therefore, the correct answer is nitrate, not nitrite.

Hydroxide is a fundamental polyatomic ion formed by one oxygen atom covalently bonded to one hydrogen atom. It is a key component of bases, providing their alkaline properties. Hydroxide ions participate in various chemical reactions, especially neutralization reactions with acids, resulting in the formation of water and salts. Its presence is critical in many biological and chemical processes, including the regulation of pH in biological systems.

NH₄⁺ is known as the ammonium ion. In chemistry, it's a positively charged polyatomic ion (ion with more than one atom). It's formed by the protonation of ammonia (NH₃). The other options in the list—nitrite (NO₂⁻), nitrate (NO₃⁻), hydroxide (OH⁻), and acetate (CH₃COO⁻)—are names of different ions and don't correspond to the given chemical formula, NH₄⁺.

Nitrogen dioxide (NO₂) is a chemical compound consisting of one nitrogen atom and two oxygen atoms. It is a significant pollutant produced by vehicles, industrial processes, and the combustion of fossil fuels. NO₂ is known for its reddish-brown color and strong, acrid smell. It plays a crucial role in the formation of smog and acid rain, making it an important compound in environmental chemistry and air quality management.

Sulfate and sulfite are both chemical compounds that contain sulfur and oxygen. The main difference between them is the number of oxygen atoms present. Sulfate has one more oxygen atom than sulfite. This difference in oxygen atoms affects their chemical properties and reactivity. Sulfate ions have a negative charge, while sulfite ions have a charge of -2. Therefore, the correct answer is that sulfate has one more oxygen than sulfite.

The sulfate ion is represented by the chemical formula SO₄²⁻. It consists of one sulfur atom (S) centrally bonded to four oxygen atoms (O) arranged in a tetrahedral shape. The sulfate ion carries a -2 charge due to the presence of four oxygen atoms, which collectively contribute to two additional negative charges. Sulfate is an essential component in various biological and environmental processes, including cellular respiration and the formation of acid rain. It's commonly found in fertilizers and is crucial for plant growth.

Bicarbonate is a crucial polyatomic ion that acts as a buffer in biological systems, particularly in maintaining the pH balance of blood and other fluids. In baking, bicarbonate reacts with acids to produce carbon dioxide gas, causing dough to rise. This property makes it a key ingredient in recipes requiring leavening agents. Furthermore, bicarbonate ions play a significant role in regulating acid-base homeostasis in the human body.

Acetate can indeed be represented as C₂H₃O₂⁻ or CH₃COO⁻. These are both valid chemical formulas for the acetate ion, which is a negatively charged ion. The formula C₂H₃O₂⁻ shows the molecular composition of acetate, with two carbon atoms, three hydrogen atoms, and two oxygen atoms. The formula CH₃COO⁻ represents the structural formula of acetate, showing the arrangement of atoms in the molecule. Both formulas are commonly used to represent acetate in chemical reactions and equations. Therefore, the statement is true.

Phosphate is an essential polyatomic ion with a charge of -3, resulting from the phosphorus atom forming five covalent bonds. This ion plays a critical role in biological systems, as it is a key component of DNA, RNA, and ATP—the energy currency of cells. Phosphate ions are vital for cellular metabolism, energy transfer, and genetic information storage. Additionally, they are commonly found in fertilizers to enhance plant growth and development.

The ion phosphate (PO₄³⁻) contains 1 phosphorus atom and 4 oxygen atoms, each carrying a charge of 2⁻, resulting in a total charge of 3⁻ for the phosphate ion. So, the correct representation is: 1 phosphorus, 4 oxygen, to the third power negative.

Permanganate is a manganese oxyanion characterized by its distinctive deep purple color, attributed to the high oxidation state of manganese in the ion. This compound is known for its strong oxidizing capabilities, making it essential in various applications such as redox reactions in analytical chemistry, disinfection processes, and as a powerful stain remover. Permanganate can react with a wide range of substances, often leading to the oxidation of organic materials and even some metals.

The correct answer is sulfite. SO₃²⁻ represents sulfite because it has a 2⁻ charge, indicating that it has gained two electrons. Sulfite is a polyatomic ion composed of one sulfur atom and three oxygen atoms. It is commonly used as a preservative in food and beverages. Sulfate, on the other hand, is represented by SO₄²⁻ and has a 2⁻ charge. It is also a polyatomic ion but consists of four oxygen atoms bonded to a sulfur atom.

Perchlorate is the most oxygen-rich oxyanion of chlorine, comprising one chlorine atom bonded to four oxygen atoms. This ion is a strong oxidizing agent, widely used in rocket propellants, fireworks, and explosives. However, perchlorate is also an environmental contaminant that poses risks to human health, particularly regarding thyroid function, as it can inhibit the uptake of iodide necessary for thyroid hormone production.

Hypochlorite is the simplest oxyanion of chlorine, containing one chlorine atom bonded to one oxygen atom. This ion is commonly found in various household bleach products and disinfectants due to its effective oxidizing properties. Its ability to release chlorine gas upon decomposition makes it useful for sanitization. Hypochlorite's role in water treatment processes is significant, as it helps eliminate bacteria and viruses, contributing to public health safety.

Oxalate is an organic ion derived from oxalic acid and consists of two carbon atoms and four oxygen atoms. It is naturally found in many plants, including spinach and rhubarb, and is known for its ability to bind calcium, potentially leading to kidney stone formation in susceptible individuals. While oxalate has some health implications, it also serves as an important metabolic intermediate in various biological processes.

Ammonium is formed when ammonia (NH₃) accepts a proton (H⁺), resulting in a positively charged polyatomic ion. Its tetrahedral structure consists of a nitrogen atom at the center bonded to four hydrogen atoms. Ammonium is significant in agriculture, as it serves as a nitrogen source in fertilizers, promoting plant growth. Additionally, ammonium compounds are utilized in cleaning products and various industrial processes due to their solubility in water.