Question

Explain the important distinction between each pair of terms: (a) peroxide and superoxide; (b) quicklime and slaked lime; (c) soap and detergent; (d) silicate and silicone; (e) sol and gel.

Short answer

Peroxides form oxygen-oxygen single bonds, while superoxides have the superoxide anion with an unpaired electron. Quicklime is \(CaO\) while slaked lime is \( Ca(OH)_2\), formed from the reaction of quicklime with water. Soaps are salts of fatty acids and usually made from natural products while detergents are synthetic, man-made substances. Silicates are naturally occurring minerals while silicones are man-made polymers. Sols are stable suspensions of small solid particles in liquid, while gels are semi-solid systems with a network that traps fluid.

Step-by-step solution

Distinguish Between Peroxide and Superoxide

Peroxides are any compounds containing an oxygen-oxygen single bond or the peroxide anion (\(O_2^{2-}\)). These can be organic (R-O-O-R') or inorganic (\(MO_2\)). Superoxides, however, are a subclass of peroxides, containing the superoxide anion (\(O_2^{-}\)), which has a single electron unpaired, making them strong oxidants.

Distinguish Between Quicklime and Slaked Lime

Quicklime, or calcium oxide (\(CaO\)), is a white, caustic, alkaline crystalline solid at room temperature. Slaked lime, or calcium hydroxide (\(Ca(OH)_2\)), is formed by the reaction of quicklime with water, in an exothermic reaction.

Distinguish Between Soap and Detergent

Soap is a type of salt of a fatty acid and is usually made from natural products like fats and lye. Detergents, on the other hand, consist of synthetic, man-made elements and are often petroleum-based. They can work effectively in hard water and usually produce foams less than soaps.

Distinguish Between Silicate and Silicone

Silicates are minerals that contain silicon, oxygen, and one or more metals. These are naturally occurring substances, which form the majority of the Earth's crust. Silicones, however, are man-made and are polymers that include any inert, synthetic compound made up of repeating units of siloxane, which is a chain of alternating silicon atoms and oxygen atoms.

Distinguish Between Sol and Gel

A sol is a colloidal suspension of very small solid particles in a continuous liquid medium. Sols are quite stable and show the Tyndall effect. Gels, on the other hand, are a semisolid system consisting of a network that traps fluid. The sol particles are bound in a continuous network, creating a structure of gel.

Key concepts

Peroxide vs Superoxide

When diving into the world of chemical compounds, understanding peroxide and superoxide is vital. Peroxides are compounds that feature an oxygen-oxygen single bond. The most well-known example is hydrogen peroxide \(H_2O_2\). In peroxides, the peroxide anion \(O_2^{2-}\) exists, often formed by bonding with organic or inorganic radicals.
Peroxides are stable and are commonly used as bleaching agents or antiseptics.

Superoxides, while related, take a slightly different path. What sets them apart is the superoxide anion \(O_2^{-}\), which carries an extra unpaired electron. This characteristic makes superoxides strong oxidants, making them more reactive than peroxides. Potassium superoxide \(KO_2\) is an example, which has applications in scrubbing carbon dioxide and generating oxygen in closed systems like submarines and space shuttles.

Quicklime vs Slaked Lime

Quicklime and slaked lime are both derivatives of calcium yet have distinct properties. Quicklime, or calcium oxide (\(CaO\)), appears as a harsh, caustic, white solid. It is highly reactive and absorbs moisture around. When quicklime interacts with water, a vigorous chemical reaction occurs, releasing heat in an exothermic process.

This process results in slaked lime, also known as calcium hydroxide (\(Ca(OH)_2\)). Slaked lime is less hazardous and has a softer, powdery texture compared to the solid form of quicklime. It finds applications in environmental treatment for neutralizing acidic soils or water.

• Quicklime: Hard, reactive, exothermic reaction with water.
• Slaked Lime: Softer, absorbs carbon dioxide to re-form as limestone.

Soap vs Detergent

Both soap and detergents serve the main purpose of cleaning, yet they originate from different sources and engage differently with water. Soap is traditionally derived from natural fats and lye (sodium hydroxide), crafting a biodegradable product. It excels in breaking down oils and grime under soft water conditions.

Detergents, meanwhile, are synthetically manufactured, often from petroleum-based components. These are powerful when it comes to modern cleaning needs, capable of producing lather even in "hard" water, which contains minerals like calcium and magnesium that impede soap's efficiency.

• Soap: Natural, works well in soft water.
• Detergents: Synthetic, effective in hard water.

Silicate vs Silicone

Silicates and silicones, while sounding similar, serve vastly different roles. Silicates belong to the mineral family that includes silicon, oxygen, and metals. These naturally occurring materials form an integral part of the Earth's crust, playing roles in geology and building materials. Common examples include quartz, feldspar, and mica.

On the flip side, silicones are synthetic polymers known for their flexibility and resilience. They're crafted from siloxane chains, consisting of alternating silicon and oxygen atoms, giving them unique properties. Silicones find use in numerous applications from cookware to medical devices due to their durability and inertness.

• Silicates: Natural, mineral-based.
• Silicones: Synthetic, versatile polymers.

Sol vs Gel

Understanding sols and gels centers around the states of matter within colloidal systems. A sol is a liquid mixture where small solid particles remain suspended within a fluid. These systems exhibit stability and are known for the Tyndall effect, where light scatters due to the tiny particles present.

A gel transitions into a more solid-like state. It starts as a sol before the particles establish a complex network that traps liquid, turning into a semi-solid. Gels find practical applications in food products, cosmetics, and pharmaceuticals.

• Sol: Stable liquid with suspended particles.
• Gel: Semi-solid with a trapped liquid network.