Explanation

Bayer's test (using dilute potassium permanganate) detects the presence of C=C double bonds in alkenes.

A positive test results in decolorization of the purple KMnO₄ solution.

Explanation

Fehling's test is used to identify aldehydes by producing a red precipitate.

Aldehydes reduce Fehling’s solution, unlike ketones.

Explanation

Complete combustion of hydrocarbons (like methane, propane, etc.) in the presence of oxygen produces:

• Carbon dioxide (CO₂)
• Water (H₂O)

Therefore, the combustion products of hydrocarbons are carbon dioxide and water.

Explanation

The chemical formula for tetrafluoroethylene is C₂F₄.

Key points about Teflon:

Chemical name: Polytetrafluoroethylene (PTFE)

Monomer: Tetrafluoroethylene

Notable property: Highly non-stick surface, often used in cooking utensils

Explanation

An element with 7 valence electrons needs 1 more electron to complete its octet.

Therefore, its valency is 1, as it tends to gain 1 electron during bonding.

Explanation

Cobalt-60, an isotope of cobalt, is widely used in radiation therapy to treat cancer.

It emits gamma rays, which help destroy cancerous cells in medical treatments.

Explanation

A polyprotic acid is an acid that can donate more than one proton (H⁺) per molecule.

1. H₃PO₄ (Phosphoric acid) → Triprotic acid (can donate 3 H⁺ ions)
2. HCN (Hydrocyanic acid) → Monoprotic (donates only 1 H⁺)
3. HCl (Hydrochloric acid) → Monoprotic

Explanation

To find the equilibrium constant (Kc) for the reaction H₂ (g) + I₂ (g) ⇌ 2HI (g), we use the formula:

Kc = [HI]² / [H₂] [I₂]

Given concentrations:

[HI] = 0.08 mol/dm³

[H₂] = 0.04 mol/dm³

[I₂] = 0.04 mol/dm³

Kc = (0.08)² / (0.04 × 0.04)

= 0.0064 / 0.0016

= 4

Explanation

The carbon dioxide (CO₂) molecule has a linear structure, with a bond angle of 180°.

Due to the two double bonds between carbon and oxygen atoms.

Explanation

A solution is a homogeneous mixture where one substance (solute) is completely dissolved in another (solvent).

Sea water: A true solution where salts (like NaCl) are completely dissolved in water.