Question

formation of glucose
balanced equation
most chemical reactions are considered reversible but are often only thermodynamically favorable in one direction. plants generate glucose from carbon dioxide and water.
the formula for glucose is \\(\ce{c6h12o6}\\).
which of the following equations represents the balanced reaction in which glucose and oxygen are formed from carbon dioxide and water?
\\(\ce{co2(g) + h2o(g) -> c6h12o6(g) + o2(g)}
\\(\ce{6co2(g) + 6h2o(g) -> c6h12o6(g) + 6o2(g)}
\\(\ce{3co2(g) + 3h2o(g) -> c3h6o3(g) + 3o2(g)}
\\(\ce{c6h12o6(g) + 6o2(g) -> 6co2(g) + 6h2o(g)}\\)

Explanation:

Step1: Recall the law of conservation of mass

In a balanced chemical equation, the number of each type of atom on the reactant side must equal the number on the product side. The reaction is the formation of glucose (\(C_6H_{12}O_6\)) and oxygen (\(O_2\)) from carbon dioxide (\(CO_2\)) and water (\(H_2O\)).

Step2: Analyze the first option

\(CO_2(g)+H_2O(g)
ightarrow C_6H_{12}O_6(g)+O_2(g)\)

• Reactants: 1 C, 3 O, 2 H
• Products: 6 C, 8 O, 12 H

Not balanced.

Step3: Analyze the second option

\(6CO_2(g)+6H_2O(g)
ightarrow C_6H_{12}O_6(g)+6O_2(g)\)

• Reactants:
• C: \(6\times1 = 6\)
• O: \(6\times2+6\times1=12 + 6=18\)
• H: \(6\times2 = 12\)
• Products:
• C: 6
• O: \(6+6\times2=6 + 12 = 18\)
• H: 12

Balanced.

Step4: Analyze the third option

\(3CO_2(g)+3H_2O(g)
ightarrow C_3H_6O_3(g)+3O_2(g)\)
The product here is \(C_3H_6O_3\) (not glucose, which is \(C_6H_{12}O_6\)), so this is incorrect.

Step5: Analyze the fourth option

\(C_6H_{12}O_6(g)+6O_2(g)
ightarrow6CO_2(g)+6H_2O(g)\)
This is the reverse reaction (combustion of glucose), not the formation of glucose from \(CO_2\) and \(H_2O\).

Answer:

B. \(6CO_2(g)+6H_2O(g)
ightarrow C_6H_{12}O_6(g)+6O_2(g)\)