Question

select the correct answer.
what type of reaction is depicted by this equation?
mgo(s) + h₂o(l) → mg(oh)₂(aq)
a. combustion
b. single-replacement
c. combination
d. decomposition

Explanation:

• Combustion: Combustion reactions involve a substance reacting with oxygen (usually from air) to produce heat and often light. In the given equation \(MgO(s)+H_2O(l)\to Mg(OH)_2(aq)\), there is no oxygen as a reactant in the sense of a combustion - like reaction (e.g., no burning in the presence of \(O_2\) to form oxides and release energy).
• Single - replacement: In a single - replacement reaction, an element reacts with a compound to produce another element and another compound. The general form is \(A + BC\to AC + B\). In the equation \(MgO(s)+H_2O(l)\to Mg(OH)_2(aq)\), there are no free elements as reactants or products, so it is not a single - replacement reaction.
• Combination (Synthesis): A combination reaction has the general form \(A + B\to AB\). Here, \(MgO\) (a compound) and \(H_2O\) (a compound) combine to form \(Mg(OH)_2\) (a single compound).
• Decomposition: A decomposition reaction has the general form \(AB\to A + B\). The given reaction is the opposite of a decomposition reaction, as it is building a more complex compound from simpler ones.

Answer:

C. combination