Approximately 5.05 g of CO2 are used when 6.50 g of O2 are produced.
Explanation:
The answer to this question is the implication that the production of 6.5g of O2 requires 5g-6g CO2, since it is 63% oxygen by mass and 37% carbon dioxide by mass (not including water vapor). This would mean that 4g-5g CO2 productions could be expected to yield 2.25 or so grams oxygen for each gram CO2 produced, depending on how low the temperature was at which the reaction took place (a product like dry ice produces only cold enough to use 1/16th its volume in volume rather than 1/200th).
