Explanation

• Ionic crystals are typically characterized by high melting points due to the strong electrostatic forces between the positively and negatively charged ions.
• The attractive forces between oppositely charged ions are strong, requiring a significant amount of energy to overcome, resulting in high melting points.

Explanation

• A non-metal atom forms an anion (a negatively charged ion) by gaining one or more electrons.
• This means that the atom acquires additional electrons to form a negative ion.

Explanation

Potassium dichromate acts as a strong oxidizing agent. 

Potassium dichromate is a powerful oxidizing agent, meaning it readily accepts electrons from other substances, causing them to be oxidized.

This characteristic is widely utilized in various chemical reactions and industrial processes where it's employed to oxidize other substances, particularly in acidic media

Explanation

 An aromatic alcohol is an alcohol where the hydroxyl group (-OH) is attached to a carbon atom that is part of an aromatic ring (like benzene).

Benzyl alcohol has the chemical formula C6H5CH2OH,

Indicating that the -OH group is attached to a carbon atom that is part of a benzene ring. 

Explanation

Cl-CH₂-COOH (chloroacetic acid) is the strongest because the electronegative chlorine atom withdraws electrons, increasing acidity.

This stabilizes the conjugate base, making it a stronger acid than formic acid (HCOOH) or acetic acid (CH₃COOH).

Explanation

NO₂ is a reddish-brown gas that gives photochemical smog its characteristic brownish color.

It is formed by the reaction of NO with oxygen in sunlight.

It is a major pollutant in urban smog.

Explanation

Raney nickel is prepared by treating a nickel-aluminum (Ni-Al) alloy with concentrated NaOH.

This process removes aluminum, leaving behind porous nickel, which acts as an excellent hydrogenation catalyst.

Explanation

Water (H₂O) is composed of 2 hydrogen atoms (1g each) and 1 oxygen atom (16g) → total molar mass = 18g.

Percentage of oxygen = (16/18) × 100 = 88.8% by mass.

Explanation

Plastic is primarily made from petrochemicals, including oil and natural gas.

They are processed to create synthetic polymers used in manufacturing.

Explanation

Surfactants reduce the surface tension of water, which is the energy required to create a surface between water and air.

By reducing surface tension, surfactants make it easier for water to spread and penetrate surfaces, which is important for cleaning and other applications.