Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2): Balance the reaction CaC2(s) + H2O(g) > Ca(OH)2(s) + C2H2(g) If you produce 13 g of C2H2, how many grams of water were required to react?

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.