Question

value: 3
identify the example of a decomposition reaction
○ a. sodium (na) and chlorine (cl) are combined to form (nacl).
○ b. magnesium (mg) and hydrochloric acid (hcl) react to form magnesium chloride (mgcl₂) and hydrogen (h₂).
○ c. 2 hydrogen peroxide molecules (h2o2) are broken down into 2 water (h2o) and 1 oxygen molecule.
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Explanation:

A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances.

• Option a: Sodium and chlorine combining to form NaCl is a combination reaction (two substances forming one), not decomposition.
• Option b: Magnesium reacting with HCl to form MgCl₂ and H₂ is a single - displacement reaction (a metal displaces hydrogen from an acid), not decomposition.
• Option c: Hydrogen peroxide (a single compound) breaks down into water and oxygen, which fits the definition of a decomposition reaction.

Answer:

c. 2 hydrogen peroxide molecules (H₂O₂) are broken down into 2 water (H₂O) and 1 oxygen molecule.