Question

Chlorine and hydrogen are combined and exposed to direct sunlight. Once exposed the chlorine and hydrogen explode and produce hydrogen chloride gas.

a. Rewrite the chemical reaction as a word equation

b. State the evidence that a chemical reaction has occurred

c. Is the reaction exothermic or endothermic? Explain your reasoning.

Answer 1

a. The chemical reaction can be rewritten as a word equation as follows:

Chlorine + Hydrogen -> Hydrogen Chloride + Explosion

b. Evidence that a chemical reaction has occurred includes the production of a new substance (hydrogen chloride gas), the release of energy (explosion), and a change in the physical properties of the reactants (change in color, odor, or temperature).

c. The reaction is likely exothermic, which means it releases energy. This is because the reaction produces a new substance (hydrogen chloride gas) and releases energy in the form of an explosion. In an endothermic reaction, the reactants would absorb energy from the surroundings.