Explanation

Explanation

1 mole of NH₃ at 300 K and 1 atm occupies 22.4 L

Because it deviates from the expected 24.6 L, showing real gas behavior.

Explanation

Scandium (Z = 21) normally has configuration [Ar] 3d¹ 4s², placing it in the d-block.

If Aufbau principle were not followed, it could instead fill differently (e.g., 4s before 3d), shifting it out of the d-block position.

Explanation

Allotropes are different forms of the same element in the same physical state.

Diamond and graphite are allotropes since both are pure carbon and one can be transformed into the other under suitable conditions.

Explanation

Alkanes are saturated hydrocarbons with only single bonds.

Their defining feature is the general formula CₙH₂ₙ₊₂.

Explanation

Ethanol (C₂H₅OH)
C₂H₅OH + 3 O₂ → 2 CO₂ + 3 H₂O
→ 3 moles of H₂O

Explanation

Step 1: Structure of H₂SO₄

• Central atom = Sulfur (S)

• Four oxygen atoms bonded to sulfur:

  • 2 double bonds with two oxygens (S=O)

  • 2 single bonds with –OH groups (S–O–H)

Step 2: Count covalent bonds around sulfur

• Each S=O double bond → 2 covalent bonds × 2 = 4 bonds

• Each S–O single bond → 1 covalent bond × 2 = 2 bonds

• Total = 6 covalent bonds around sulfur

Step 3: Electrons in covalent bonds
Each covalent bond = 2 electrons → 6 × 2 = 12 electrons

Explanation

The rate of diffusion/effusion of a gas is inversely proportional to the square root of its molecular mass (Graham’s law).

Lighter gases spread faster in the laboratory than heavier gases.

Explanation

Step 1: Molar mass of glucose
C₆H₁₂O₆ = (6×12) + (12×1) + (6×16) = 72 + 12 + 96 = 180 g/mol.

Step 2: Moles in 18 g

Step 3: Molecules in 0.1 mol
1 mol = 6.022 × 10²³ molecules
0.1 mol = 6.022 × 10²² molecules.

Step 4: Carbon atoms per molecule
Each glucose molecule has 6 carbon atoms.
Total carbon atoms = 6 × (6.022 × 10²²) = 3.6132 × 10²³.

Explanation

Chlorine free radicals (Cl·) from CFCs react with ozone (O₃), breaking it into O₂ and ClO·.

This chain reaction depletes the ozone layer and one Cl· can destroy thousands of ozone molecules.