Question

Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose C6H12O6 and oxygen O2 gas. Calculate the moles of carbon dioxide needed to produce 1.8mol of oxygen. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.

Answer 1

Answer:

                    1.8 moles of O₂

Explanation:

                     The balance chemical equation for said double replacement (photosynthesis) reaction is as follow;

                           6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

According to balance chemical equation,

                 6 moles of O₂ are produced by  =  6 moles of CO₂

So,

                1.8 moles of O₂ will be produced by  =  X moles of O₂

Solving for X,

                     X =  1.8 mol × 6 mol / 6 mol

                     X =  1.8 moles of O₂

Stoichiometric problems in which moles are given and moles or other reactant or product asked are the simplest problems. One should only write the balanced chemical equation and perform above method to find the required moles.