Question

scientists sometimes want to show whether more energy is used or released during a chemical process. they do this by adding the word energy to the chemical equation. if more energy is used than is released during a chemical process, \energy\ should appear on the same side of the equation as the reactants. if more energy is released than is used, \energy\ should appear on the same side of the equation as the products.
the energy used in photosynthesis is light energy, which is captured by pigments in plant cells called chlorophyll.
which of the following balanced chemical equations accurately summarizes photosynthesis?
6co₂ + 6h₂o + light energy → c₆h₁₂o₆ + 6o₂
6co₂ + 6h₂o → c₆h₁₂o₆ + 6o₂ + light energy

Explanation:

Step1: Recall photosynthesis energy use

Photosynthesis uses light energy (reactant side).

Step2: Analyze energy placement rule

If energy is used (more used than released), it's on reactant side (left of arrow).

Step3: Evaluate the equations

First equation: \( 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{light energy}
ightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \) has light energy (used) on reactant side. Second equation has energy on product side (implies released, which is incorrect for photosynthesis).

Answer:

\( 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{light energy}
ightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \)