Question

Examine the following equations and choose the statement with the correct classification and explanation:

I. 2Ca + O2 → 2CaO
II. 6CO2 + 6H2O → C6H12O6 + 6O2
III. 2 KClO3 → 2KCl + 3O2
IV. Zn + 2HCl → ZnCl2 + H2
A) Reaction IV is a double replacement reaction because Zinc (Zn) is replacing the Hydrogen (H) to produce Zinc Chloride (ZnCl2).
B) Reaction III is a decomposition reaction because one reactant is breaking apart to produce two products.
C) Reaction II is a combustion reaction because oxygen is produced during the reaction.
D) Reaction I is a synthesis reaction because a metal is reacting with oxygen.

Answer 1

The statement is correct; Reaction I is classified as a synthesis reaction because it involves a metal reacting with oxygen to form an oxide, which is a single new product indicative of such reactions.

Step-by-step explanation:

Synthesis reactions involve combining two or more elements or compounds to form a new compound. In the given example, sodium metal reacts with chlorine gas to produce sodium chloride, which is a classic example of a synthesis reaction. The reaction formula 2 Na (s) + Cl2 (g) → 2 NaCl (s) clearly shows that two reactants combine to form a single product, which is sodium chloride. This is indicative of a synthesis reaction because a new compound is formed from the direct combination of simpler substances.

Similarly, when a metal reacts with oxygen, the typical product formed is an oxide of that metal. Since the question specifies Reaction I involves a metal reacting with oxygen and implies the formation of a single product, we can conclude that an oxide is formed. Therefore, the classification as a synthesis reaction is correct. Such a reaction also fits the characterisation of a redox reaction, which is another way to classify many synthesis reactions involving the formation of compounds from their elements.