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

A reaction in which heat is absorbed is called an endothermic reaction.

These reactions lower the temperature of their surrounding area, thereby creating a cooling effect.

Explanation

Diffusion is the process where particles move from an area of high concentration to low concentration.

Ink spreads evenly in water due to molecular motion, resulting in uniform distribution.

Explanation

According to Valence Shell Electron Pair Repulsion (VSEPR) theory, XeF₄ (xenon tetrafluoride) has a square planar geometry.

Xenon in XeF₄ has six electron pairs around it: four bonding pairs and two lone pairs.

Explanation

Aluminum is the most abundant metal in the Earth's crust, and the third most abundant element therein, after oxygen and silicon.

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Explanation

A covalent bond forms when two non-metals share electrons.

This type of bond results in the formation of molecules like H₂O and CO₂.

Explanation

Given reaction:

NO(g) + CO₂(g) ⇌ NO₂(g) + CO(g)

Initial moles:

NO = 4 mol

CO₂ = 0.9 mol

NO₂ = 0

CO = 0

At equilibrium:

CO₂ = 0.1 mol

→ So, change in CO₂ = 0.9 - 0.1 = 0.8 mol consumed

→ Therefore, 0.8 mol of NO also reacted

→ 0.8 mol each of NO₂ and CO formed

Equilibrium moles:

NO = 4 - 0.8 = 3.2 mol

CO₂ = 0.1 mol

NO₂ = 0.8 mol

CO = 0.8 mol

Equilibrium expression:

K = [NO2][CO]/[NO][CO2] = (0.8)(0.8)/(3.2)(0.1) = 0.64/0.32 = 0.2

Explanation

Aldol condensation requires at least one α-hydrogen (hydrogen on the carbon next to the carbonyl group).

Benzaldehyde and formaldehyde lack α-hydrogens, so they cannot undergo Aldol condensation.

Explanation

The d subshell has 5 orbitals, each can hold 2 electrons, so total 10 electrons.

This is standard in electron configuration rules in chemistry.

Explanation

The formula to calculate max electrons in an orbit is 2n², where n = orbit number.

1st orbit (n = 1): 2 × 1² = 2 electrons

2nd orbit (n = 2): 2 × 2² = 8 electrons

For the 3rd orbit (n = 3): 2 × 3² = 18 electrons