Question

an electric current can be used to decompose water (h₂o) into oxygen (o₂) and hydrogen (h₂). which model accurately represents this reaction?

Explanation:

Step1: Write the balanced chemical equation

The chemical equation for the decomposition of water is \(2H_2O
ightarrow O_2 + 2H_2\). This means that for every 2 water molecules (\(H_2O\)), we get 1 oxygen molecule (\(O_2\)) and 2 hydrogen molecules (\(H_2\)).

Step2: Analyze each model

• In the first model: 1 \(H_2O\) molecule decomposes. This does not follow the balanced equation (\(2H_2O\) should decompose).
• In the second model: 2 \(H_2O\) molecules decompose to give 1 \(O_2\) molecule and 2 \(H_2\) molecules. This matches the balanced chemical equation \(2H_2O

ightarrow O_2 + 2H_2\).

• In the third model: 2 \(H_2O\) molecules decompose but the number of \(H_2\) molecules is 1 (should be 2 as per the balanced equation).
• In the fourth model: 1 \(H_2O\) molecule decomposes (does not follow the balanced equation).

Answer:

The second model (the one with two \(H_2O\) molecules on the left - hand side, one \(O_2\) molecule and two \(H_2\) molecules on the right - hand side) accurately represents the reaction.