Question

the reactants and products of photosynthesis are made of the same amounts of hydrogen, carbon, and oxygen atoms. when 6 molecules of carbon - dioxide gas (co₂) react with 6 molecules of water (h₂o), the atoms in these molecules are rearranged to produce 1 molecule of glucose (c₆h₁₂o₆) and 6 molecules of oxygen gas (o₂). which chemical equation is balanced and represents the overall process of photosynthesis? 6co₂ + 6h₂o → 6c₆h₁₂o₆ + 6o₂ 6co₂ + 6h₂o → c₆h₁₂o₆ + 6o₂ co₂ + 6h₂o → 6c₆h₁₂o₆ + o₂ co₂ + h₂o → c₆h₁₂o₆ + 6o₂

Explanation:

Step1: Check atom - counts in each option

For a balanced chemical equation of photosynthesis, we need to ensure that the number of carbon (C), hydrogen (H), and oxygen (O) atoms is the same on both sides of the equation.
The general process of photosynthesis has 6 molecules of carbon - dioxide ($CO_2$) and 6 molecules of water ($H_2O$) as reactants and 1 molecule of glucose ($C_6H_{12}O_6$) and 6 molecules of oxygen ($O_2$) as products.

• In the reactants:
• From $6CO_2$, the number of C atoms is 6, and the number of O atoms is 12. From $6H_2O$, the number of H atoms is 12 and the number of O atoms is 6. So, in total, we have 6 C atoms, 12 H atoms, and 18 O atoms in the reactants.
• In the products:
• In $C_6H_{12}O_6$, we have 6 C atoms, 12 H atoms, and 6 O atoms. In $6O_2$, we have 12 O atoms. So, in total, we have 6 C atoms, 12 H atoms, and 18 O atoms in the products.

Step2: Analyze each option

• Option 1: $6CO_2+6H_2O

ightarrow6C_6H_{12}O_6 + 6O_2$

• On the left - hand side, we have 6 C, 12 H, and 18 O. On the right - hand side, we have 36 C, 72 H, and 48 O. This is not balanced.
• Option 2: $6CO_2+6H_2O

ightarrow C_6H_{12}O_6+6O_2$

• On the left - hand side: C: 6, H: 12, O: 18. On the right - hand side: C: 6, H: 12, O: 6 + 12=18. This is balanced.
• Option 3: $CO_2+6H_2O

ightarrow6C_6H_{12}O_6+O_2$

• On the left - hand side, we have 1 C, 12 H, and 8 O. On the right - hand side, we have 36 C, 72 H, and 38 O. This is not balanced.
• Option 4: $CO_2+H_2O

ightarrow C_6H_{12}O_6+6O_2$

• On the left - hand side, we have 1 C, 2 H, and 3 O. On the right - hand side, we have 6 C, 12 H, and 18 O. This is not balanced.

Answer:

$6CO_2+6H_2O
ightarrow C_6H_{12}O_6+6O_2$ (Option 2)