Which of the following is an example of a gel? MCQ with Answer and Explanation

Explanation:
Isoelectronic species have the same total number of electrons. Carbon monoxide (CO) has 6 (from C) + 8 (from O) = 14 electrons. Nitrogen molecule (N2) has 7 + 7 = 14 electrons. Therefore, N2 is isoelectronic with CO. O2 has 16, CO2 has 22, and NO has 15 electrons.

Explanation:
In Zn + 2HCl, Zn is oxidized (0 to +2) and H⁺ is reduced (+1 to 0). So it is a redox reaction. The other reactions are double displacement (A), combination without oxidation state change (B, D). Redox requires change in oxidation states.

Explanation:
Combined gas law: P₁V₁/T₁ = P₂V₂/T₂. Given P₂ = 2P₁, T₂ = 2T₁. So V₂ = V₁ × (P₁/P₂) × (T₂/T₁) = 22.4 × (1/2) × (2/1) = 22.4 L. Pressure increase tries to halve volume, temperature increase tries to double volume; they cancel out. So volume remains unchanged. This assumes ideal behavior.