Explanation

To determine the slowest rate of diffusion, we use Graham’s law:

Rate of diffusion ∝ 1/√Molar mass

Molar masses:

• O₂ = 32 g/mol
• N₂ = 28 g/mol
• CH₄ = 16 g/mol
• NH₃ = 17 g/mol

Heavier gases diffuse more slowly.

O₂ has the highest molar mass among the options, so its diffusion is slowest.

Explanation

Argon is a commonly used gas used to fill incandescent light bulbs.

It increases bulb life by preventing the tungsten filaments from deteriorating too quickly.

Other gases are also used in lighting such as:

• Helium
• Neon
• Nitrogen
• Krypton

Explanation

Most plastics are derived from petroleum and natural gas, which are non-renewable fossil fuels.

Large-scale plastic production reduces fossil fuel reserves.

Explanation

Potassium (K) has a +1 oxidation state and selenium (Se) has a -2 oxidation state.

Two K⁺ ions combine with one Se²⁻ ion to form K₂Se.

Explanation

In molten NaCl, the ionic lattice breaks down.

Na⁺ and Cl⁻ ions become free to move, allowing electric conduction.

Explanation

Hydrocarbons are organic compounds composed only of carbon and hydrogen atoms.

Examples: Methane (CH₄), Ethylene (C₂H₄), Acetylene (C₂H₂).

Explanation

Aliphatic compounds are open-chain organic compounds (straight or branched chains).

They include alkanes, alkenes, and alkynes.

Explanation

Given:

Volume of CO₂ = 1.12 liters

At STP, 1 mole of any gas occupies 22.4 liters.

Molar mass of CO₂ = 44 g/mol

Let's find the number of moles:

moles = volume / 22.4 L/mol

moles = 1.12 L / 22.4 L/mol

moles = 0.05 mol

Weight = moles × molar mass

Weight = 0.05 mol × 44 g/mol

Weight = 2.2 g

Explanation

A Gooch crucible is used to filter precipitates or suspensions, such as potassium permanganate (KMnO₄) solutions.

It is made of porous material (e.g., asbestos or glass fiber) for fine filtration.

Explanation

A double bond (C=C) indicates that the compound is unsaturated.

Unsaturated compounds can add more atoms (e.g., hydrogen) across the double bond.