Chemistry

Calcium carbonate is a metal carbonate. When an acid reacts with dilute hydrochloric acid and forms carbon dioxide gas & solution of calcium chloride. Reaction: CaCO3 + 2HCl(a) = CaCl2 + H2O(l) + CO2(g) Change in Free Energy: ΔG(20C) = -25.2kJ (negative, so the reaction runs) Change in Enthalpy: ΔH(20C) = +79.9kJ (positive, so the reaction is endothermic)

Moles, Molecules and Atom are always confusing but after watching this video you can solve any type of questions.

Mesomeric has higher stability compare to hyperconjugation and inductive effect. Mesomeric effect accounts for the resonance stabilization of the molecule due to delocalization of charge. For carbocation stabilization (+m) effect is required. Means electron donating should be more.

Fe[(H2O)6]2+ has higher unpaired electrons compare to [Cr(H2O) 6] 3+ so Fe[(H2O)6]2+ is higher Paramagnetism.