Why does the ground turn black after we burn items there or any surface?​

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .

Intermolecular forces. question i need with: the only intermolecular forces that affect non polar molecules are forces.

An electron moved from a lower energy level to a higher energy level. what most likely happened during the transition? a random amount of light was released. a fixed amount of energy was absorbed. a fixed amount of energy was released. a random amount of light was absorbed.