#1: 2h2o + 2k (s) 2koh (l) + 2h2 (g) is an example of which type of reaction?
a. single-displacement
b. combustion
c. decomposition
d. double-displacement

D) double-displacement

Explanation:

In a displacement reaction, one or more atoms replace one or more atoms of a given molecule to form a new one.

In this case, two atoms of K replace two atoms of H in the water molecules two form H2 and KOH.

Is double because two displacement happen in the global reaction equation.  

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